Here at the Blog, we love the learned intermediary rule.  We’ve chronicled the rule’s steady expansion as it now has precedential support in all fifty states.  “Every state in the country, along with the District of Columbia and Puerto Rico, has adopted the learned intermediary doctrine in some iteration.”  Dearinger v. Eli Lilly & Co., 510 P.3d 326, 329 (Wash. 2022). We’ve discussed how it applies to all types of prescription medical products (specifically, medical devices as well as drugs).  We’ve pointed out that it protects pharmacies as well as product manufacturers.  We have headcounts and 50-state surveys.  In fact, it’s gotten to the point that we’ve discussed the learned intermediary rule so many times from so many angles, that there are probably too many places to look efficiently.

We’re hoping to address the problem of too much information in too many places with this post.  Here, we’re combining in one place the jurisdictional information about the rule from our headcounts with the substantive information from our 50-state surveys.  This post, on a state-by state basis, not only provides the decisions from highest-level courts to adopt the learned intermediary rule itself, but also the best precedents for its application to medical devices, biologics (fewer cases after the Vaccine Act), and pharmacists.

One final note before getting to the meat of this quite long (81+ pages in Word) post − obviously, we believe the rationale for the rule would support its application in all of these contexts, even if a particular state doesn’t have authority in each area, so don’t let lack of directly on-point precedent in any particular state stop you from arguing for the learned intermediary rule.  This post is intended to help defense counsel do just that.  So, fill in those holes.

What we’re doing initially is what the Blog did with the failure to report 50-state survey, which was of similar length.  We’re going to break it into three posts over three weeks, so people who want to read them can do so without spending all day.  When that’s done, behind the scenes, we will add the three pieces back together so that our users can find everything in one place – our original goal.

Here goes.  This is Part 2, which will at the end of the process be consolidated with the other two posts.

Kentucky

The Kentucky Supreme Court adopted the learned intermediary rule in Larkin v. Pfizer, Inc., 153 S.W.3d 758 (Ky. 2004), answering a certified question “yes.”  Id. at 761.  “Although the rule largely applies to prescription drugs, some courts have extended it to cases involving prescription medical implants and devices.”  Id. (citations omitted).  Larkin comprehensively discussed the rationales supporting the rule.  Id. at 763-64.  See Hyman & Armstrong, P.S.C. v. Gunderson, 279 S.W.3d 93, 109 (Ky. 2008) (in Larkin “we adopted the learned intermediary doctrine”).  The Sixth Circuit, applying Kentucky law, has also applied the learned intermediary rule to medical devices.  Thacker v. Ethicon, Inc., 47 F.4th 451, 460 (6th Cir. 2022) (“[i]n medical device cases, Kentucky applies the learned intermediary rule”).  In Snawder v. Cohen, 749 F. Supp. 1473, 1480 (W.D. Ky. 1990), the learned intermediary rule applied to a biologic.  A Kentucky federal court has also barred pharmacist claims under the rule.  Foister v. Purdue Pharma, L.P., 295 F. Supp.2d 693, 706 (E.D. Ky. 2003) (“The learned intermediary doctrine provides that once a drug manufacturer has warned physicians of the dangers of the drug, the pharmacy’s liability is cut off by the physician’s knowledge.).

Louisiana

Louisiana intermediate appellate courts have followed the learned intermediary rule consistently, and the Louisiana Supreme Court has never accepted an appeal from any of those decisions.  The first decision was Cobb v. Syntex Laboratories, Inc., 444 So.2d 203 (La. App. 1983), holding:

The manufacturer of a prescription drug has the obligation to inform the prescribing physician of any potentially adverse side effects or risks from the drug’s use. . . .  The manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with the drug.  The manufacturer of the drug has fulfilled its obligation when it has informed the prescribing and treating physicians of the risks of harm from the drug so that they may intelligently decide on its use and advise the patient.  The doctor acts as an informed intermediary.  The decision to use the drug in a particular circumstance rests with the doctor and the patient, not with the manufacturer.

Id. at 205 (citation omitted).  See also Kampmann v. Mason, 921 So.2d 1093, 1094 (La. App. 2006) (“Under the learned intermediary the drug manufacturer has no duty to warn the customer directly. The manufacturer’s duty is fulfilled when the prescribing or treating physician is informed of the risks from the drug use.”) (drug); Marks v. Ohmeda, Inc., 871 So.2d 1148, 1157 (La. App. 2004) (quoting Brown) (medical device); Brown v. Glaxo, Inc., 790 So.2d 35, 38 (La. App. 2000) (“[U]nder the ‘learned intermediary doctrine,’ the doctor acts as an informed intermediary between the drug company and the patient. Thus, a drug manufacturer has a duty to warn the prescribing doctor, rather than the patient, of potential risks associated with the use of the drug.”) (drug); Calhoun v. Hoffman-LaRoche, Inc., 768 So.2d 57, 61 (La. App. 2000) (drug) (quoting Cobb); Mikell v. Hoffman-LaRoche, Inc., 649 So.2d 75, 79 (La. App. 1994) (“[A] drug manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with its product.  The obligation to the consumer is fulfilled when the prescribing or treating physician is informed of any potential side effects or risks”) (drug); Rhoto v. Ribando, 504 So.2d 1119, 1123 (La. App. 1987) (“A drug manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with its product. The obligation to the consumer is fulfilled when the prescribing or treating physician is informed of the risks of harm from the drug.”) (drug); Kinney v. Hutchinson, 468 So.2d 714, 717-18 (La. App. 1985) (drug) (quoting Cobb).

The learned intermediary rule also precludes pharmacy-related warning claims in Louisiana.

The pharmacist does not . . . have a duty to question a judgment made by the physician as to the propriety of a prescription or to warn customers of the hazardous side effects associated with a drug, either orally or by way of the manufacturer’s package insert.

Gassen v. East Jefferson General Hospital, 628 So.2d 256, 259 (La. App. 1993).  See Id. at 258 (“Under both common law and under Louisiana jurisprudence a pharmacist does not have a duty to warn a patient of adverse reactions.”).  Accord Guillory v. Doctor X, 679 So.2d 1004, 1010 (La. App. 1996) (quoting Gassen).

Federal appellate decisions applying Louisiana law routinely follow the learned intermediary rule.

Louisiana applies the “learned intermediary doctrine” to products liability claims involving prescription drugs.  Under this doctrine, a drug manufacturer discharges its duty to consumers by reasonably informing prescribing physicians of the dangers of harm from a drug.

Stahl v. Novartis Pharmaceuticals Corp., 283 F.3d 254, 265 (5th Cir. 2002) (drug) (citation omitted).  Accord In re Taxotere (Docetaxel) Products Liability Litigation, 994 F.3d 704, 708 (5th Cir. 2021) (drug); Grenier v. Medical Engineering Corp., 243 F.3d 200, 205 n.4 (5th Cir. 2001) (medical device); Theriot v. Danek Medical, Inc., 168 F.3d 253, 256 (5th Cir. 1999) (medical device); Willett v. Baxter International, Inc., 929 F.2d 1094, 1098 (5th Cir. 1991) (medical device); Anderson v. McNeilab, Inc., 831 F.2d 92, 93 (5th Cir. 1987) (drug).

We didn’t find a Louisiana biologic learned intermediary rule decision.

Maine

The Maine Supreme Judicial Court has never addressed the learned intermediary rule.  The First Circuit, in Violette v. Smith & Nephew Dyonics, Inc., 62 F.3d 8, 13 (1st Cir. 1995), applied the rule to a medical device case.

While the Supreme Judicial Court of Maine has not decided the matter, the general rule regarding medical devices (and, more frequently and by analogy, prescription drugs) is that the manufacturer must warn the physician − the so-called “learned intermediary” − and not the patient directly.

Id. at 13 (citations omitted).  Accord Doe v. Solvay Pharmaceuticals, Inc., 153 F. Appx. 1, 3 (1st Cir. 2005) (“This court already has decided that Maine courts would adopt that rule”) (citing Violette) (drug), affirming, 350 F. Supp.2d 257, 270-71 (D. Me. 2004).  Accord Novak v. Mentor Worldwide LLC, 287 F. Supp.3d 85, 95-96 (D. Me. 2018) (“a manufacturer fulfills its duty to warn a consumer of the dangers inherent in a product when the manufacturer has adequately warned the consumer’s physician”) (medical device); Herzog v. Arthrocare Corp., 2003 WL 1785795, at *8 (D. Me. March 21, 2003) (medical device).  See also In re Davol, Inc./C.R. Bard, Inc., Polypropylene Hernia Mesh Products Liability Litigation, 2024 WL 363235, at *3 (S.D. Ohio Jan. 31, 2024) (“Under the learned intermediary doctrine, a manufacturer’s duty to warn is fulfilled when the manufacturer has adequately warned the physician, rather than the plaintiff himself.”) (medical device) (applying Maine law); In re Davol, Inc./C.R. Bard, Inc., Polypropylene Hernia Mesh Products Liability Litigation, 2023 WL 2478553, at *12 (S.D. Ohio Jan. 31, 2024) (“This Court finds the reasoning in Tardy and in the numerous federal trial and appellate court decisions applying Maine law to be persuasive.  Therefore, the Court finds that the learned intermediary doctrine should apply in this case.”) (medical device) (applying Maine law).

A Maine trial court applied the learned intermediary rule to bar claims against a pharmacist in Tardy v. Eli Lilly & Co., 2004 WL 1925536 (Me. Super. Aug. 3, 2004), a state trial court applied the rule to bar claims against a pharmacist.

[H]olding pharmacists liable would not serve as an incentive to safety since the pharmacist presented with a prescription ordered by a duly licensed physician is not at liberty to substitute his or her judgment of the product’s safety for the patient for that of the physician.  Based on the foregoing, the court adopts the majority view and holds that the learned intermediary doctrine applies to the present action.

Id. at *2-3 (citation and quotation marks omitted).

Apparently, no Maine law court has ever addressed the learned intermediary rule in a biologic context.

Maryland

The Maryland Supreme Court applied the learned intermediary rule to pharmacies in Rite Aid Corp. v. Levy-Gray, 894 A.2d 563 (Md. 2006):

[T]he “learned intermediary” doctrine . . . applies to the tripartite relationship between the drug manufacturer, the prescribing physician, and the patient. . . .  As stated by the Restatement (Third) of Torts, “the traditional rules [are] that drug and medical-device manufacturers are liable only when their products contain manufacturing defects or are sold without adequate instructions and warnings to prescribing and other health-care providers”. . . .  The “learned intermediary” doctrine has been extended to provide a defense to pharmacies and pharmacists by the courts of other jurisdictions.

Id. at 577 (citations omitted).  An earlier Maryland decision, Nolan v. Dillon, 276 A.2d 36, 40 (Md. 1971), has been cited (including by us) as applying the learned intermediary rule, but did not do so explicitly.  See Gourdine v. Crews, 955 A.2d 769, 782-83 (Md. 2008).

The Maryland intermediate appellate court in Gourdine applied the learned intermediary rule, which the high court’s subsequent affirmance did not reach:

With respect to prescription drugs, Maryland law recognizes the “learned intermediary” doctrine, which provides that manufacturers need only warn the prescribing physician and not the patient directly.  Stated alternatively, under the learned intermediary doctrine, the manufacturer of a prescription drug has no duty to directly warn patients.

Gourdine v. Crews, 935 A.2d 1146, 1150 (Md. Spec. App. 2007), aff’d on other grounds, 955 A.2d 769 (Md. 2008).  Accord Larson v. Abbott Laboratories, Inc., 2018 WL 3479236, at *9 (Md. Spec. App. July 19, 2018) (“In pharmaceutical failure to warn cases, the ‘learned intermediary’ doctrine provides an exception to a manufacturer’s duty to warn the consumer directly; instead, the duty to warn runs to the prescribing physician.  Therefore, a pharmaceutical manufacturer has a duty to warn physicians or other personnel authorized to prescribe drugs by state law.”) (citations and quotation marks omitted) (biologic).

Federal appellate courts have likewise viewed Maryland as applying the learned intermediary rule in prescription medical product liability litigation.  Doe v. Miles Laboratories, Inc., 927 F.2d 187, 194 (4th Cir. 1991) (“A pharmaceutical manufacturer must warn physicians or other medical personnel authorized to prescribe drugs by state law.”) (biologic); Hofherr v. Dart Industries, Inc., 853 F.2d 259, 263 (4th Cir. 1988) (“Any obligation of [a pharmacist] to the consumer to warn was not to warn the consumer or the franchisee of the prescription drug, rather to warn the physician who prescribed it.”).

Somehow, no appellate case applying Maryland law has had occasion to apply the learned intermediary rule in a medical device case.  Numerous federal district courts have done so.  Here are the published ones:  Morris v. Biomet, Inc., 491 F. Supp.3d 87, 104 (D. Md. 2020); Miller v. Bristol-Myers Squibb Co., 121 F. Supp.2d 831, 838 (D. Md. 2000); Lee v. Baxter Healthcare Corp., 721 F. Supp. 89, 95 (D. Md. 1989), aff’d, 898 F.2d 146 (4th Cir. 1990).

Massachusetts

Massachusetts adopted the learned intermediary rule in MacDonald v. Ortho Pharmaceutical Corp., 475 N.E.2d 65 (Mass. 1985), a prescription drug case.

The rule in jurisdictions that have addressed the question of the extent of a manufacturer’s duty to warn in cases involving prescription drugs is that the prescribing physician acts as a “learned intermediary” between the manufacturer and the patient, and the duty of the ethical drug manufacturer is to warn the doctor, rather than the patient, although the manufacturer is directly liable to the patient for a breach of such duty.

Id. at 68 (citation and quotation marks omitted).

The rule was extended to pharmacists in Cottam v. CVS Pharmacy, 764 N.E.2d 814, 820 (Mass. 2002):

A number of jurisdictions have addressed the issue [of pharmacy duty to warn], and the overwhelming majority hold that, in general, a pharmacy has no duty to warn its customers of side effects.  We similarly hold that, generally, a pharmacy has no duty to warn its customers of the side effects of prescription drugs.

Other jurisdictions have reached this result by extending to pharmacies the “learned intermediary doctrine,” a rule commonly applied to drug manufacturers. . . .   The learned intermediary doctrine in this context provides that a prescription drug manufacturer’s duty to warn of dangers associated with its product runs only to the physician; it is the physician’s duty to warn the ultimate consumer. . . .  

This court has already recognized the learned intermediary doctrine in the context of prescription drug manufacturers.  Because the physician is the appropriate person to perform the duty of warning a patient of the possible side effects of prescription drugs, we now extend this doctrine to pharmacies.

Id. at 819-21 (citations and quotation marks and footnote omitted).

No appellate Massachusetts state court decision has applied the learned intermediary rule in a medical device case.  Numerous federal decisions have done so.  Here are the reported ones.  Plourde v. Sorin Group USA, Inc., 23 F.4th 29, 36 (1st Cir. 2022); Knowlton v. Deseret Medical, Inc., 930 F.2d 116, 120 n.2 (1st Cir. 1991); Corrigan v. Covidien LP, 748 F. Supp. 3d 1, 12 (D. Mass. 2024); In re Fresenius GranuFlo/NaturaLyte Dialysate Products Liability Litigation, 691 F. Supp. 3d 280, 299 (D. Mass. 2023); Plourde v. Sorin Group USA, Inc., 517 F. Supp. 3d 76, 88-89 (D. Mass. 2021); Taupier v. Davol, Inc., 490 F. Supp.3d 430, 447 (D. Mass. 2020); Langlois v. American Medical Systems, Inc., 462 F. Supp.3d 1, 4 (D. Mass. 2020); Mongeon v. Ethicon, Inc., 456 F. Supp.3d 298, 302 (D. Mass. 2020); Lareau v. Page, 840 F. Supp. 920, 933 (D. Mass. 1993), aff’d, 39 F.3d 384 (1st Cir. 1994).

Prescription biologics are also subject to the learned intermediary rule under Massachusetts law.  Calisi v. Abbott Laboratories, 2013 WL 5441355, at *3 (D. Mass. Sept. 27, 2013).

Michigan

In Smith v. E.R. Squibb & Sons, Inc., 273 N.W.2d 476, 479 (Mich. 1979), the Michigan Supreme Court stated, “A manufacturer of a prescription drug has a legal duty to warn the medical profession, not the patient, of any risks inherent in the use of the drug which the manufacturer knows or should know to exist.”  Id. at 479 (citations omitted).  That sure looked like a precedential holding, but a later decision of the same court called that “dictum.”  In re Certified Questions, 358 N.W.2d 873, 877 (Mich. 1984).  Nothing further has been decided by the Michigan Supreme Court.

Michigan intermediate appellate decisions have followed the Smith language and applied the learned intermediary rule in a prescription drug case.

[T]he “learned intermediary” doctrine . . . applied to manufacturers of prescription drugs, who are required to warn only the prescribing physician, who acts as a “learned intermediary” between the manufacturer and consumer. . . .  The “learned intermediary” doctrine has been adopted by many other jurisdictions, where it has almost unanimously been applied for all prescription drugs.

Mowery v. Crittenton Hospital, 400 N.W.2d 633, 637 (Mich. App. 1986) (citations omitted).  Accord King-Washington v. Eli Lilly & Co., 394 F. Appx. 827, 828-29 (2d Cir. 2010) (prescription drug) (applying Michigan law).

The rule was applied to medical devices in Brown v. Drake-Willock International, Ltd., 530 N.W.2d 510 (Mich. App. 1995):

[I]n the absence of a clear legal duty imposed on defendant manufacturers to directly warn plaintiffs, plaintiffs have failed to state a claim upon which they may recover. 

We now hold that the reasoning and policy behind the learned intermediary rule applies not only to prescription drugs, but also to prescription devices. . . .  Under the learned intermediary rule, the hospital or physician was the proper recipient of necessary information or warnings, not plaintiff. . . .  [D]efendant manufacturers had no duty to warn plaintiff in this case because of the learned intermediary rule.

Id. at 516 (citations omitted).

Dunn v. Lederle Laboratories, 328 N.W.2d 576, 580-81 (Mich. App. 1982), applied the learned intermediary rule to vaccines/biologics.

Warnings generally must be calculated to reach the ultimate consumer.  An exception exists for drugs dispensed in a manner requiring a physician to weigh the risks and benefits of a drug’s use on a particular patient. With these drugs the doctor, and not the patient, must be warned by the manufacturer.

Id. at 580-81 (citation and footnote omitted).

Other Michigan decisions apply the learned intermediary rule to pharmacists.  Adkins v. Mong, 425 N.W.2d 151, 152 (Mich. App. 1988) (“defendant pharmacy in this case had no duty to warn plaintiff of the potential side effects of the substances it was dispensing to plaintiff in accordance with the prescriptions submitted, all of which were valid on their face”); Stebbins v. Concord Wrigley Drugs, Inc., 416 N.W.2d 381, 386-88 (Mich. App. 1987) (“a pharmacist has no duty to warn the patient of possible side effects of a prescribed medication where the prescription is proper on its face and neither the physician nor the manufacturer has required that any warning be given to the patient by the pharmacist”).

Minnesota

More than fifty years ago, the Minnesota Supreme Court stated that “[t]he manufacturer has no duty to warn the lay public regarding prescription drugs.”  Mulder v. Parke Davis & Co., 181 N.W.2d 882, 885 n.1 (Minn. 1970).  That court reiterated this holding in Gray v. Badger Mining Corp., 676 N.W.2d 268, 275 (Minn. 2004), stating that in Mulder “we recognized that the learned intermediary defense was available in a claim for failure to warn of the dangers of a drug.”  Id. at 275-76.  Gray was not a prescription medical product case.

Lots of federal courts apply the rule to medical devices.  Kapps v. Biosense Webster, Inc., 813 F. Supp.2d 1128, 1152 (D. Minn. 2011), held:

Under the learned-intermediary doctrine, a maker of drugs or medical devices has a duty to warn only doctors (the learned intermediaries) − and not patients − about the dangers associated with a drug or medical device. Thus, the learned-intermediary doctrine forecloses a patient’s failure-to-warn claim if a drug company or medical-device manufacturer provides an adequate warning to the patient’s doctor.

Id. at 1152 (citations omitted).  Most of the rest, however, are not reported.  See In re Bard Implanted Port Catheter Products Liability Litigation, 2026 WL 622645, at *9 (D. Ariz. March 5, 2026) (applying Minnesota law); Juliar v. Ethicon, Inc., 2022 WL 23624, at *2 (D. Minn. Jan. 3, 2022); Dolan v. Boston Scientific Corp., 2021 WL 698777, at *3 (D. Minn. Feb. 23, 2021); Marshall v. Smith & Nephew, Inc., 2020 WL 362803, at *7 (D. Minn. Jan. 22, 2020); Perry v. Boston Scientific Family, 2016 WL 10637082, at *5 (Mag. D. Minn. Dec. 1, 2016), adopted, 2017 WL 44845 (D. Minn. Jan. 4, 2017); Thompson v. Zimmer Inc., 2013 WL 5406628, at *3 (D. Minn. Sept. 25, 2013); Wehner v. Linvatech Corp., 2008 WL 495525, at *4 (D. Minn. Feb. 20, 2008); Johnson v. Zimmer, Inc., 2004 WL 742038, at *9 (D. Minn. March 31, 2004); In re Orthopedic Bone Screw Litigation, 1999 WL 628688, at *14 (D. Minn. March 8, 1999), aff’d mem., 221 F.3d 1343 (8th Cir. 2000); Bruzer v. Danek Medical, Inc., 1999 WL 613329, at *6 (D. Minn. March 8, 1999); Greiner v. Sofamor, S.N.C., 1999 WL 716891, at *5 (D. Minn. March 8, 1999); Mozes v. Medtronic, Inc., 14 F. Supp.2d 1124, 1130 (D. Minn. 1998); Kociemba v. G.D. Searle & Co., 680 F. Supp. 1293, 1305-06 (D. Minn. 1988).  See also In re Bard Implanted Port Catheter Products Liability Litigation, 2026 WL 622645, at *9 (D. Ariz. March 5, 2026) (applying Minnesota law).

We haven’t found any Minnesota biologic or pharmacy cases involving the rule.

Mississippi

In Mississippi, the learned intermediary rule is now required by statute as to both drugs and medical devices.  Miss. Code §11-1-63(c)(ii) (requiring warnings “in the case of a prescription drug, medical device or other product that is intended to be used only under the supervision of a physician or other licensed professional person,” be given to “a physician or other licensed professional who prescribes the drug, device or other product”).

The statute was not a big change from Mississippi common law.  The Mississippi Supreme Court has consistently followed the rule.

The general rule is that where prescription drugs are concerned, a manufacturer’s duty to warn only extends to physicians and not to laymen.  If the language of the warning is adequate then the drug manufacturer ordinarily is freed from liability.  The “learned intermediary” doctrine is the basis for this rule.

Janssen Pharmaceutica, Inc. v. Bailey, 878 So.2d 31, 57 (Miss. 2004) (citation and quotation marks omitted).  Janssen quoted Wyeth Laboratories, Inc. v. Fortenberry, 530 So.2d 688, 691 (Miss. 1988), the first Mississippi high court decision to adopt the learned intermediary rule – which did so in a vaccine/biologic context.  Accord Bennett v. Madakasira, 821 So.2d 794, 804 (Miss. 2002) (“Under Mississippi law, as in virtually every jurisdiction in a prescription drug case, a manufacturer of a prescription drug has no duty to warn the patient, consumer, or general public of adverse effects.”) (drug).

In Moore v. Memorial Hospital, 825 So.2d 658 (Miss. 2002), the court extended the learned intermediary rule to pharmacists.

We . . . extend the learned intermediary doctrine to pharmacists.  As one court has stated, “the cornerstone of the learned intermediary doctrine is the ability of the physician to intervene between the drug and the patient, and to make an informed decision as to the course of treatment based on the physician’s knowledge of the drug as well as the propensities of the patient.”  The physician is best situated to know the propensities of a drug and to know the needs and characteristics of his patient.

Id. at 664 (citation omitted).  Moore also noted that the learned intermediary rule “has been extended to insulate from liability the manufacturers of medical devices available through physicians.”  Id. at 662 n.6 (citing Cather v. Catheter Technology Corp., 753 F. Supp. 634 (S.D. Miss. 1991)).

Missouri

Over 50 years ago, the Missouri Supreme Court held, in Krug v. Sterling Drug, Inc., 416 S.W.2d 143 (Mo. 1967), that the “basic rule and duty” in products liability litigation was:

Where the drug is a prescription drug, the manufacturer has a duty to properly warn the doctor of the dangers involved.  It is incumbent upon the manufacturer to bring the warning home to the doctor.

Id. at 146-47 (citations and quotation marks omitted).  That court has not decided another learned intermediary case since.  Accord Johnson v. Upjohn Co., 442 S.W.2d 93, 95 (Mo. App. 1969) (“In the case of prescription drugs . . . warning to the medical profession in such manner is all that is required and constitutes warning to the patient as well.”) (citing Krug); Brinkley v. Pfizer, Inc., 772 F.3d 1133, 1137 (8th Cir. 2014) (“Missouri too adheres to the learned intermediary doctrine.”) (citation and quotation marks omitted).

A Missouri intermediate appellate court applied the learned intermediary rule to a biologic in Doe v. Alpha Therapeutic Corp., 3 S.W.3d 404 (Mo. App. 1999), pointing out that “Missouri courts adhere to the learned intermediary doctrine” and that “the manufacturer has a duty to properly warn the doctor of the dangers involved.”  Id. at 419.

The learned intermediary doctrine is a corollary to the rule that a manufacturer of prescription drugs or products discharges its duty to warn by providing the physician with information about risks associated with those products.  The physician acts as a “learned intermediary” between the manufacturer and the patient and any warning given to the physician is deemed a warning to the patient.

Id. (citations omitted).

The Eighth Circuit  applied the rule to medical devices.  Kirsch v. Picker International, Inc., 753 F.2d 670, 67 (8th Cir. 1985).

Missouri courts have held that in cases involving prescription drugs, the manufacturer has a duty to properly warn the doctor of the danger involved.  The physician acts as a “learned intermediary” between the manufacturer and the patient.  Thus, a warning to the doctor is deemed a warning to the patient; the manufacturer need not communicate directly with all ultimate users of prescription drugs.

Id. at 671.

Since Missouri appellate precedent concerning the rule is somewhat old, here are some more recent trial court cases demonstrating that it continues to be applied in Missouri prescription medical product liability litigation.  Seals v. Wright Medical Technologies, Inc., 2022 WL 6096818, at *14 (E.D. Mo. Oct. 7, 2022) (“Missouri courts apply the learned-intermediary doctrine in medical-equipment or medical-device cases involving failure-to-warn claims.) (citations omitted); Davis v. Eisai, Inc., 2021 WL 4810704, at *2 (W.D. Mo. Oct. 14, 2021) (“to the degree Plaintiff’s failure to warn claims are premised on [plaintiff’s] failure to warn anyone other than Plaintiff’s doctor, they fail to state a claim and are dismissed”); Rash v. Boston Scientific Corp., 2020 WL 8455124, at *4 (W.D. Mo. Nov. 12, 2020) (“because of the application of the learned intermediary doctrine, [plaintiff’s] claim for negligent failure to warn is viable only to the extent [she] alleges [defendant] failed to warn her treating physician of the risks associated with Product”); Bayes v. Biomet, Inc., 2020 WL 5095346, at *12 (E.D. Mo. Aug. 28, 2020) (“Missouri courts apply the learned intermediary doctrine in prescription drug and medical equipment or device cases involving failure to warn claims.”); Abt v. Ethicon, Inc., 2020 WL 4887022, at *2 (E.D. Mo. Aug. 20, 2020) (same); Guilford v. Boston Scientific Corp., 2020 WL 1668279, at *2 (W.D. Mo. April 3, 2020) (“Because Defendant owed no duty to Plaintiff or the medical community at large, Plaintiff’s claims for failure to warn must be dismissed to the extent they are premised on Defendant’s failure to warn anyone other than Plaintiff’s physician.”); Redd v. DePuy Orthopaedics, Inc., 48 F. Supp.3d 1261, 1270 (E.D. Mo. 2014) (“The learned intermediary doctrine provides that a drug manufacturer has a duty to warn a physician of the risks involved with its product. The physician then acts as a ‘learned intermediary’ between the manufacturer and the physician’s patient so that any warning given to the physician is deemed a warning to the patient.”).

We did not find any Missouri precedent applying the learned intermediary rule to a pharmacist.

Montana

In Hill v. Squibb & Sons, 592 P.2d 1383, 1387-88 (Mont. 1979), the court recognized that “As a general rule, the duty of a drug manufacturer to warn of the dangers inherent in a prescription drug is satisfied if adequate warning is given to the physician who prescribes it.”) (citations omitted).  In Stevens v. Novartis Pharmaceuticals Corp., 247 P.3d 244 (Mont. 2010), the court cautioned that while “[t]he learned intermediary doctrine has been widely accepted, in some form, for the better part of the past century,” id. at 492, its contours in terms of “expansion of the possible class of learned intermediaries” were less certain” and that “a variety of different healthcare providers may be considered learned intermediaries.”  Id. at 493.  Thus, Stevens ultimately “concur[red] with authorities who consider the learned intermediary to be the healthcare professional actually responsible for making decisions related to the patient’s care.”  Id. at 495.

The learned intermediary rule in Montana has been applied to medical devices.  Dalbotten v. C.R. Bard, Inc., 2023 WL 157735, at *3 (D. Mont. Jan. 11, 2023) (“Under the learned intermediary doctrine, a medical or pharmaceutical manufacturer’s duty to warn runs to the prescribing and treating physicians, rather than necessarily to the patients themselves.”).

We don’t know of any Montana cases involving the rule’s application in cases involving biologics or pharmacists.

Nebraska

The Nebraska Supreme Court adopted the learned intermediary rule in Freeman v. Hoffman-La Roche, Inc., 618 N.W.2d 827 (Neb. 2000). 

Pharmaceutical products have historically been treated differently in regard to a duty to warn. . . .  [I]n cases involving prescription drugs, it is widely held that the duty to warn extends only to members of the medical profession and not to the consumer.  This concept [is] known as the learned intermediary doctrine. . . .  The learned intermediary doctrine is provided for in § 6(d) of the Third Restatement. . . .

We have not specifically adopted the learned intermediary doctrine as the applicable test for determining whether a manufacturer may be liable for a warning defect in prescription drug cases.  However, with a few exceptions . . ., the doctrine is followed in virtually all jurisdictions that have considered whether to adopt it.  The doctrine as stated in the Third Restatement has also been adopted in other jurisdictions.  We adopt § 6(d) of the Third Restatement.  Accordingly, we apply the learned intermediary doctrine to [this] case.

Id. at 841-42 (citations and block quotations omitted).

The learned intermediary rule has also been applied, under Nebraska law to medical devices.

Although Freeman involved a “prescription drug,” the Restatement treats “medical device[s]” no differently, which suggests that the Nebraska Supreme Court would, if faced with the question, apply the learned-intermediary doctrine to devices.

Ideus v. Teva Pharmaceuticals USA, Inc., 986 F.3d 1098, 1101 (8th Cir. 2021).

The relevant consumer for design defect claims is the patient, not the physician. “Although not stated explicitly in Nebraska case law, it is implicit that the consumer or user of a medical device or prescription drug is the patient − not the physician.”).

Thelen v. Somatics, LLC, 156 F.4th 1115, 1125 (11th Cir. 2025) (applying Nebraska law) (quoting Langner v. Boston Scientific Corp., 492 F. Supp. 3d 925, 933 (D. Neb. 2020)).

A trial court in another state applied the Nebraska learned intermediary rule to a biologic.  Cleary v. Biogen Idec, Inc., 2017 WL 8226624, at *11 (Mass. Super. Sept. 8, 2017).

We haven’t found any Nebraska cases involving the rule’s application to a defendant pharmacist.

Nevada

Nevada has adopted the learned intermediary rule.  In Klasch v. Walgreen Co., 264 P.3d 1155, 1159 (Nev. 2011), involving a pharmacy defendant, the Nevada Supreme Court held:

Traditionally, the learned-intermediary doctrine has been used to insulate drug manufacturers from liability in products-liability lawsuits.  Under the learned-intermediary doctrine, a drug manufacturer is immune from liability to a patient taking the manufacturer’s drug so long as the manufacturer has provided the patient’s doctor with all relevant safety information for that drug.  It is then up to the patient’s doctor − who has the benefit of knowing the patient’s specific situation − to convey to the patient any information that the doctor deems relevant.

Jurisdictions adopting the learned-intermediary doctrine in the context of pharmacist/customer tort litigation have put forth a similar rationale:  that between the doctor and the pharmacist, the doctor is in the best position to warn the customer of a given medication’s generalized risks. . . .  In this sense, the learned-intermediary doctrine preserves the pharmacist’s role as a conduit for dispensing much-needed prescription medications.

Because we believe that these public-policy considerations are sound, we adopt the learned-intermediary doctrine in the context of pharmacist/customer tort litigation.

Id. at 1158-59 (footnotes omitted).  See Sanchez v. Wal-Mart Stores, Inc., 221 P.3d 1276, 1280-84 (Nev. 2009) (also rejecting pharmacist warning liability without mentioning the rule).

Previously, a majority of the Nevada Supreme had applied the learned intermediary rule in a biologic/vaccine case in Allison v. Merck & Co., 878 P.2d 948 (Nev. 1994), but not all in the same opinion.  A two-justice plurality acknowledged the learned intermediary rule, but applied the “mass immunization” exception:

[W]e do not believe that [the prescriber’s] advice . . . that “it was time” for [plaintiff] to receive his MMR II vaccine is the type of individualized medical judgment contemplated by the learned intermediary defense. . . .  Accordingly, the mass immunization exception does apply to this case.

Id. at 958 n.16.  As the plurality indicated, the two-justice Allison dissent considered “summary judgment [to be] appropriate in this case [given] the applicability of the . . . ‘learned intermediary defense.’” Id.  That made a majority of the court.  Here’s what the dissent in Allison said:

[T]he learned intermediary defense . . . is one that this court has never addressed.  A learned intermediary [is] as a medical expert, such as a prescribing physician, whose task is to weigh the benefits of any medication against possible dangers and to make an individualized medical judgment bottomed on a knowledge of both patient and palliative.  The pharmaceutical company’s duty, in selling prescription drugs, is to warn only the prescribing physician, who acts as a ‘learned intermediary’ between manufacturer and consumer.

Id. at 969 (citations and quotation marks omitted).  Unlike the plurality, the dissent found that “the prescribing physician[] was a learned intermediary in this case,” and thus no exception to the rule applied.  Id. at 969 (a manufacturer “should not be held liable simply because the learned intermediary failed to perform his duty to warn his patient”).  No justice in Allison rejected the learned intermediary rule itself.

No Nevada appellate decisions have applied the learned intermediary rule in the medical device context.  However, a raft of federal district court decisions have done so. Whipple v. C.R. Bard, Inc., 2024 WL 1345227, at *5-6 (D. Nev. March 30, 2024); Carter v. Johnson & Johnson, 2022 WL 4625960, at *3 (D. Nev. Sept. 30, 2022); Hix v. Zimmer Biomet Holdings, Inc., 2022 WL 946914, at *5-6 (D. Nev. March 29, 2022); Carter v. Ethicon, Inc., 2021 WL 1226531, at *2, 4 (D. Nev. March 31, 2021); Young v. Ethicon, Inc., 2021 WL 6101637, at *4 (D. Nev. Jan. 29, 2021); Heinrich v. Ethicon, Inc., 455 F. Supp.3d 968, 973-74 (D. Nev. 2020); Miller v. Depuy Synthes Sales, Inc., 2019 WL 4016207, at *6 (D. Nev. Aug. 26, 2019); Phillips v. C.R. Bard, Inc., 2014 WL 7177256, at *9 (D. Nev. Dec. 16, 2014); Moses v. Danek Medical, Inc., 1998 WL 1041279, at *4-5 (D. Nev. Dec. 11, 1998); Kioudjian v. Technogym USA Corp., 2018 WL 3702005, at *1 (Nev. Dist. June 26, 2018).

As discussed, the Nevada Supreme Court has applied the learned intermediary rule to prescription drugs, but only in the pharmacy context.  Several Nevada law decisions by recognize that the same considerations apply to prescription drugs generally, including the Ninth Circuit in Kwasniewski v. Sanofi-Aventis U.S., LLC, 637 F. Appx. 405, 406 (9th Cir. 2016) (“holding that under Nevada law, there is no duty to warn on the part of a non-prescribing therapist”).  Nevada trial courts also apply the rule to prescription drugs.  Kwasniewski v. Sanofi-Aventis U.S. LLC, 2018 WL 1567851, at *4 (D. Nev. March 30, 2018); Flowers v. Eli Lilly & Co., 2015 WL 12622058, at *2-3 (D. Nev. July 10, 2015); Harrelson v. Boehringeringelheim Pharmaceuticals, Inc., 2024 WL 3585784, at *10 (Nev. Dist. May 15, 2024); Adams v. Teva Parenteral Medicines, Inc., 2024 WL 1944157, at *3-5 (Nev. Dist. Feb. 4, 2024).

Stephens v. Zoetis, Inc., 2026 WL 837353, at *1-2 (D. Nev. March 25, 2026), applied the learned intermediary rule applies to veterinary drugs under Nevada law.

New Hampshire

The only New Hampshire state court decision to address the learned intermediary rule is a trial court decision following it in the drug context:

The learned intermediary doctrine creates an exception to the general rule that one who markets goods must warn foreseeable ultimate users about the inherent risks of his products and, in the prescription drug context provides that a drug manufacturers duty is limited to the obligation to advise the prescribing physician of any potential dangers that may result from the use of the drug.

State v. Purdue Pharma Inc., 2018 WL 4566129, at *6 (N.H. Super. Sept. 18, 2018).

Federal courts have also held that New Hampshire would follow the rule.  The First Circuit has applied the learned intermediary rule twice in New Hampshire prescription drug cases.  Brochu v. Ortho Pharmaceutical Corp., 642 F.2d 652, 656 (1st Cir. 1981) (“In cases involving ethical drugs, the manufacturer must warn the physician, not the patient.”) (citations omitted); McCue v. Norwich Pharmacal Co., 453 F.2d 1033, 1035 (1st Cir. 1972) (“the New Hampshire court would follow others in imposing upon a drug manufacturer an affirmative duty to warn the medical profession of the dangerous side effects that might result”).

Federal district courts interpreting New Hampshire law likewise apply the learned intermediary rule to medical device cases. 

[T]he learned intermediary doctrine holds that a manufacturer’s duty to warn regarding the risks associated with a product runs to a patient’s treating physician (or other learned intermediary) rather than directly to the patient.  The parties and the court agree that, as a matter of New Hampshire law, the learned intermediary doctrine applies to duties owed by pharmaceutical manufacturers. . . .  [W]hile plaintiff argues that there is an unresolved question as to whether the doctrine applies to medical device manufacturers, plaintiff offers no rationale for distinguishing between the pharmaceutical and the medical device contexts for purposes of the doctrine.  Courts that have considered the matter have uniformly found that the doctrine is applicable with equal force in both contexts.

Luna v. Atrium Medical Corp., 561 F. Supp.3d 62, 69-70 (D.N.H. 2021) (citations omitted).  Accord O’Neil v. Somatics, LLC, 2022 WL 4611938, at *8 (D.N.H. Sept. 30, 2022) (“I have no doubt that the court will follow the many courts in other jurisdictions that have applied the [learned intermediary] doctrine in medical device cases.”); cf. Nelson v. Dalkon Shield Claimants Trust, 1994 WL 255392, at *4 (D.N.H. June 8, 1994) (“it is generally accepted that in a case involving medical products prescribed or used by a physician or trained medical personnel, the warning runs to the physician not the patient.”) (citation and quotation marks omitted) (pre-1976 IUD)

We found no pharmacist or biologic cases from New Hampshire.

New Jersey

As to prescription drugs, the learned intermediary rule is required by statute in New Jersey.  N.J. Stat. §2A:58C-4.

An adequate product warning or instruction is one that a reasonably prudent person in the same or similar circumstances would have provided with respect to the danger and that communicates adequate information on the dangers and safe use of the product, taking into account the characteristics of, and the ordinary knowledge common to, the persons by whom the product is intended to be used, or in the case of prescription drugs, taking into account the characteristics of, and the ordinary knowledge common to, the prescribing physician.

(Emphasis added).  See In re Accutane Litigation, 194 A.3d 503, 508 (N.J. 2018) (“New Jersey has adopted the ‘learned intermediary’ doctrine, which recognizes that a prescribing doctor has the primary responsibility of advising the patient of the risks and benefits of taking a particular medication.”) (citations omitted).

Likewise, the New Jersey Supreme Court has recognized that the rule applies to all prescription medical products.  Perez v. Wyeth Laboratories, Inc., 734 A.2d 1245, 1257 (N.J. 1999), applied the rule to a product that “exhibit[ed] characteristics both of a medical device implanted in the body and of a drug.”  Id. at 1257.

With respect to drugs and medical devices, our state law has adopted the “learned intermediary” doctrine, under which a pharmaceutical manufacturer generally discharges its duty to warn the ultimate user of prescription drugs by supplying physicians with information about the drug’s dangerous propensities.  This doctrine recognizes that a prescribing doctor has the primary responsibility of advising the patient of the risks and benefits of taking a particular medication.  Thus, it is the physician’s responsibility to pass on to the parties the information that enables the patient to use the product safely. . . .  Where a failure-to-warn case involves something advised by a physician, such as a prescription drug or a medical device, the issue is whether the warning should have been given to the prescribing physician.

Hrymoc v. Ethicon, Inc., 249 A.3d 191, 217 (N.J. Super. App. Div. 2021) (citations and quotation marks omitted), aff’d on other grounds, 297 A.3d 1245 (N.J. 2023).

Niemiera v. Schneider, 555 A.2d 1112, 1117 (N.J. 1989), applied the learned intermediary rule in a vaccine case:

In New Jersey, as elsewhere, we accept the proposition that a pharmaceutical manufacturer generally discharges its duty to warn the ultimate user of prescription drugs by supplying physicians with information about the drug’s dangerous propensities.  This concept is known as the “learned intermediary” rule because the physician acts as the intermediary between the manufacturer and the consumer. . . .  We are satisfied that sufficient reasons exist with respect to the . . . vaccine to conclude that the “learned intermediary” doctrine should apply.

Id. at 1117 (citation and footnote omitted).

Shamy v. Gamao, 2023 WL 6939135 (N.J. Super. App. Div. Oct. 20, 2023), recognized that the rule also applies in product liability cases brought against pharmacies.

[T]he [learned intermediary] doctrine applies to pharmacies that accurately fill prescriptions written by physicians in amounts and at frequencies within reasonable medical standards. . . .  Because the decision to prescribe a specific drug involves an analysis of the patient’s unique condition and a balancing of the risks and benefits of a given drug, the cases extending the learned intermediary doctrine to pharmacists reason that imposing a duty to warn on the pharmacist would intrude on the doctor-patient relationship and would force the pharmacist to practice medicine without a license.

Id. at *5 (citations and quotation marks omitted).

New Mexico

While the New Mexico Supreme Court has never addressed the learned intermediary rule, New Mexico intermediate appellate courts have applied it repeatedly.  As to prescription drugs, Richards v. Upjohn Co., 625 P.2d 1192, 1195 (N.M. App. 1980), declared:

A drug manufacturer has a duty to warn the medical profession of the dangers of its drugs which it knew or should have known to exist.  The manufacturer is liable to a patient who suffers injuries from a drug as a result of the manufacturer’s breach of its duty to warn the doctor of the dangers of the drug.

Id. at 1195-96 (citations omitted).  Accord Silva v. SmithKlineBeecham Corp., 2013 WL 4516160, at *2-3 (N.M. App. Feb. 7, 2013) (quoting and following Hines); Serna v. Roche Laboratories, Division of Hoffman-LaRoche, Inc., 684 P.2d 1187, 1189 (N.M. App. 1984) (“Where the product is a prescription drug, the manufacturer’s duty to warn is fulfilled if it warns the physician, not the patient.”) (citation omitted).  Hines v. St. Joseph’s Hospital, 527 P.2d 1075, 1077 (N.M. App. 1974), treated a biologic (blood) as a prescription drug, holding that “The [evidence] establish[es] that blood is a prescription drug.  Ordinarily the manufacturer’s duty to warn of the dangers of prescription drugs is to the attending physician, not the patient.”  Id. at 1077 (citations omitted).

In a medical device case, Perfetti v. McGahn Medical, 662 P.2d 646 (N.M. App. 1983), held:

The parties dispute as to whom the warning was due − plaintiff or her surgeon.  The evidence is uncontradicted that federal law restricted this prosthesis “to sale by or on the order of a licensed physician”; that plaintiff had no contact with defendant and received no warning from defendant.  A manufacturer of a product which is obtainable only through the services of a physician, fulfills its duty if it warns the physician of the dangers attendant upon its use, and need not warn the patient as well.

Id. at 650 (citations and quotation marks omitted).  Accord Jones v. Minnesota Mining & Manufacturing Co., 669 P.2d 744, 748 (N.M. App. 1983) (“under the circumstances of these cases, any warnings to be given would be to the radiotherapists”).

We don’t know of any New Mexico pharmacist cases.

Finally, we point out that Nowell v. Medtronic Inc., 372 F. Supp.3d 1166 (D.N.M. 2019), aff’d, 2021 WL 4979300 (10th Cir. Oct. 27, 2021), applied the learned intermediary rule in a medical device case:

Pursuant to the learned-intermediary doctrine, the prescribing physician acts as a learned intermediary between a prescription drug manufacturer and the ultimate user, and the manufacturer satisfies its duty to warn by providing adequate warnings to the prescribing physician.  The learned intermediary doctrine states that once a manufacturer warns a doctor about a drug’s inherent dangers, it has fulfilled its legal duty to provide a warning. . . .  “The overwhelming majority of jurisdictions to address this issue apply the learned intermediary doctrine to define a pharmaceutical company’s duty to warn of risks associated with the use of a prescription drug.

Id. at 1128-29 (citations and quotation marks omitted).  We mention this because Nowell was decided by the same New Mexico judge who had, several years earlier, questioned whether New Mexico followed the rule at all.  See Rimbert v. Eli Lilly & Co., 577 F. Supp. 2d 1174, 1214-16 (D.N.M. 2008).  Should any plaintiff challenge the learned intermediary rule in New Mexico citing Rimbert, the proper response is that Nowell demonstrates that the same judge has since recanted that outré position and accepts the learned intermediary rule as New Mexico law.

New York

The New York Court of Appeals adopted the learned intermediary (also a/k/a “informed intermediary” in NY) rule in Spensieri v. Lasky, 723 N.E.2d 544, 549 (N.Y. 1999), and Martin v. Hacker, 628 N.E.2d 1308, 1311 (N.Y. 1993).  Martin, in a prescription drug case, held:

Warnings for prescription drugs are intended for the physician, whose duty it is to balance the risks against the benefits of various drugs and treatments and to prescribe them and supervise their effects.  The physician acts as an “informed intermediary” between the manufacturer and the patient; and, thus, the manufacturer’s duty to caution against a drug’s side effects is fulfilled by giving adequate warning through the prescribing physician, not directly to the patient.

Id. at 601 (citations omitted).  Similarly, Spensieri recognized:

The learned intermediary doctrine focuses on the scope of a drug manufacturer’s duty to warn of the dangers of using the drug in question.  That duty is fulfilled by giving adequate warning to the prescribing physician.  The physician must then balance the risks and benefits of various drugs and treatments and act as an “informed intermediary” between manufacturer and patient.

Id. at 549 (Martin citations omitted).

While New York’s highest court has not applied the learned intermediary rule in a medical device case, numerous other New-York-law appellate decisions have done so.  Bravman v. Baxter Healthcare Corp., 984 F.2d 71, 75 (2d Cir. 1993) (“In cases such as this one, the duty to warn is owed to the medical community and, more specifically, to the treating physician who is to act as an ‘informed intermediary’ between the manufacturer and patient.”) (citation omitted); Fane v. Zimmer, Inc., 927 F.2d 124, 129 (2d Cir. 1991) (The “device is not available to the public, but rather is available only by prescription and thus . . . information is disseminated to physicians and the medical community rather than to the patient directly.  Warnings are furnished to the medical community as the ‘informed intermediary’ between the manufacturer and the patient.”); Tomaselli v. New York & Presbyterian Hospital, 728 F. Appx. 41, 43 (2d Cir. 2018) (“plaintiffs’ strict liability claims against the defendants fail under the informed intermediary doctrine”); Donovan v. Centerpulse Spine Tech Inc., 416 F. Appx. 104, 107 (2d Cir. 2011) (“Under New York law, the physician acts as an ‘informed intermediary’ between the manufacturer and the patient; and, thus, the manufacturer’s duty to caution against a device’s side effects is fulfilled by giving adequate warning through the treating] physician”); Silverstein v. CoolSculpting – Zeltiq Aesthetics, Inc., 229 N.Y.S.3d 44, 46 (App. Div. 2025) (“Because the [device] is a FDA Class II medical device that requires a prescription, [defendant’s] duty to warn runs to physicians, not directly to patients.”); Mulhall v. Hannafin, 841 N.Y.S.2d 282, 285 (App. Div. 2007) (“The manufacturer’s duty, under New York law, is to warn the medical community, not the patient of the product’s risk.”) (citation omitted); Cutroneo v. Dryer, 784 N.Y.S.2d 247, 249 (App. Div. 2004) (“Where the risks of a medical device are thoroughly disclosed to the treating physician, the manufacturer is insulated from liability for a failure to warn the patient of same.”) (citation omitted); Banker v. Hoehn, 718 N.Y.S.2d 438, 440 (App. Div. 2000) (“Under the doctrine of ‘learned intermediary,’ the manufacturer of the medical device satisfies its duty to warn of potential adverse effects when it adequately warns medical professionals who use the device in the treatment of patients”); Bukowski v. CooperVision Inc., 592 N.Y.S.2d 807, 809 (App. Div. 1993) (“The informed intermediary doctrine has been extended to apply to certain medical devices”) (citations omitted).

The learned intermediary rule also protects New York pharmacists unless “the prescription was so clearly contraindicated that ordinary prudence required the pharmacist to take additional measures.”  Abrams v. Bute, 27 N.Y.S.3d 58, 71 (App. Div. 2016).

Since “the physician acts as an ‘informed intermediary’” . . . “it is the prescribing physician who is responsible for exercising the professional judgment needed to determine whether a particular course of treatment is appropriate for a given patient.  Courts have been reluctant to impose a standard of care on pharmacists that would go beyond the need to accurately fill a prescription and require pharmacists to exercise their own professional judgment in a manner that could conflict with that of the prescribing physician.

Id. at 65-66 (citations omitted).  Accord In re New York County Diet Drug Litigation, 691 N.Y.S.2d 501, 502 (App. Div. 1999); Bichler v. Willing, 397 N.Y.S.2d 57, 559 (App. Div. 1977). 

The New York learned intermediary rule also applies to biologics.  Wholey v Amgen, Inc., 2017 WL 931326 at *9 (N.Y. Sup. March 8, 2017), aff’d, 86 N.Y.S.3d 16 (App. Div. 2018).

North Carolina

In North Carolina, the learned intermediary rule applies, by statute, to prescription drugs.

Notwithstanding subsection (a) of this section, no manufacturer or seller of a prescription drug shall be liable in a products liability action for failing to provide a warning or instruction directly to a consumer if an adequate warning or instruction has been provided to the physician or other legally authorized person who prescribes or dispenses that prescription drug for the claimant unless the United States Food and Drug Administration requires such direct consumer warning or instruction to accompany the product.

N.C. Gen. Stat. §99B-5(c).

Under North Carolina law, courts have repeatedly applied the learned intermediary rule to prescription medical devices.  Asby v. Medtronic, Inc., 673 F. Supp.3d 787, 794 (E.D.N.C. 2023) (“Although North Carolina law explicitly applies the learned intermediary doctrine to prescription drugs, the doctrine also applies to medical devices.”); Teague v. Johnson & Johnson, 578 F. Supp.3d 743, 750 (E.D.N.C. 2022) (“the learned intermediary doctrine would apply just as equally to the manufacturer of a medical device”); Smith v. Ethicon, Inc., 2020 WL 3256926 at *2 (M.D.N.C. June 16, 2020) (“Although the North Carolina Supreme Court has not spoken on whether the limitation on pharmaceutical liability outlined in §99B-5(c) likewise extends to medical devices . . ., several federal courts . . . have presumed that it does.”); Carlson v. Boston Scientific Corp., 2015 WL 5732107 (W.D.N.C. Sept. 30, 2015) (“the North Carolina Supreme Court would apply the learned intermediary doctrine in a case involving a medical device such as this”), aff’d, 856 F.3d 320 (4th Cir. 2017); Block v. Woo Young Medical Co., 937 F. Supp.2d 1028, 1035 n.5 (D. Minn. 2013) (“North Carolina adheres to the learned intermediary doctrine”) (applying North Carolina law); Baraukas v. Danek Medical, Inc., 2000 WL 223508 at *4 (M.D.N.C. Jan. 13, 2000) (“where a defendant manufactures a product which is dispensed to patients by doctors, rather than directly, the defendant has a duty to warn only the doctor, rather than the patients North . . . Carolina courts would adhere to the learned intermediary doctrine.”); Padgett v. Synthes, Ltd. (U.S.A.), 677 F. Supp. 1329, 1335 (W.D.N.C. 1988) (“warnings when given in the insert to the physician were sufficient notice to Plaintiff”), aff’d, 872 F.2d 418 (4th Cir. 1989).

Under North Carolina law, the learned intermediary rule has also been applied to biologics.  In re Gardasil Products Liability Litigation, 724 F. Supp.3d 474, 489 n.17 (W.D.N.C. 2024) (“North Carolina . . . recognize[s] the learned intermediary doctrine”), aff’d, 151 F.4th 178 (4th Cir. 2025); Cowley v. Abbott Laboratories, Inc., 476 F. Supp.2d 1053, 1060 (W.D. Wis. 2007) (treating a biologic as a “drug” under §99B-5(c)) (applying North Carolina law); Foyle v. Lederle Laboratories, 674 F. Supp. 530, 536 (E.D.N.C. 1987) (“The doctor is responsible for gathering the information, weighing the dangers and benefits, and making a decision in the best interest of the patient.  This analysis supports the “learned intermediary” doctrine.”).

A North Carolina appellate court rejected pharmacist liability on learned intermediary grounds in Batiste v. American Home Products Corp., 231 S.E.2d 269, 274-76 (N.C. App. 1977).

Here the drug purchased by plaintiff was not available to the general public in the sense that it was available for purchase by any customer who came in the drug store. . . .  It was available only to those who had previously seen their physician and obtained from the physician a prescription directing the druggist to supply the drug.  Obviously the plaintiff patient did not rely on the druggist. . . .  This reliance had been properly placed with her physician.

Id. at 276.

This is the end of Part 2.  Look for Part 3 next week.

Here at the Blog, we love the learned intermediary rule.  We’ve chronicled the rule’s steady expansion as it now has precedential support in all fifty states.  “Every state in the country, along with the District of Columbia and Puerto Rico, has adopted the learned intermediary doctrine in some iteration.”  Dearinger v. Eli Lilly & Co., 510 P.3d 326, 329 (Wash. 2022). We’ve discussed how it applies to all types of prescription medical products (specifically, medical devices as well as drugs).  We’ve pointed out that it protects pharmacies as well as product manufacturers.  We have headcounts and 50-state surveys.  In fact, it’s gotten to the point that we’ve discussed the learned intermediary rule so many times from so many angles, that there are probably too many places to look efficiently.

We’re hoping to address the problem of too much information in too many places with this post.  Here, we’re combining in one place the jurisdictional information about the rule from our headcounts with the substantive information from our 50-state surveys.  This post, on a state-by state basis, not only provides the decisions from highest-level courts to adopt the learned intermediary rule itself, but also the best precedents for its application to medical devices, biologics (fewer cases after the Vaccine Act), and pharmacists.

One final note before getting to the meat of this quite long (81+ pages in Word) post − obviously, we believe the rationale for the rule would support its application in all of these contexts, even if a particular state doesn’t have authority in each area, so don’t let lack of directly on-point precedent in any particular state stop you from arguing for the learned intermediary rule.  This post is intended to help defense counsel do just that.  So, fill in those holes.

Alabama

We don’t have to go past supreme court decisions in Alabama.  This state was a relatively early adopter of the learned intermediary rule in Stone v. Smith, Kline & French Laboratories, 447 So.2d 1301, 1305 (Ala. 1984).

We cannot quarrel with the general proposition that where prescription drugs are concerned, the manufacturer’s duty to warn is limited to an obligation to advise the prescribing physician of any potential dangers that may result from the drug’s use.  This special standard for prescription drugs is an understandable exception to the . . . general rule that one who markets goods must warn foreseeable ultimate users of dangers inherent in his products.

Id. at 1304-05 (citation and quotation marks omitted).  Other Alabama Supreme Court cases applying the learned intermediary rule to prescription drugs are Blackburn v. Shire U.S., Inc., 380 So.3d 354, 359 (Ala. 2022) (“The learned-intermediary doctrine recognizes the role of the physician as a learned intermediary between a drug manufacturer and a patient.”) (citation and quotation marks omitted); and Wyeth, Inc. v. Weeks, 159 So.3d 649, 672-74 (Ala. 2014), but read them before citing.

The Alabama Supreme Court applied the learned intermediary rule to medical devices in Morguson v. 3M Corp., 857 So.2d 796, 801-02 (Ala. 2003) (defendant “had no duty to provide warnings to [plaintiff] rather, [defendant’s] duty was to warn the physicians and perfusionists . . . who used the [device]”).

The Alabama Supreme Court has also repeatedly recognized that the learned intermediary rule protects pharmacists.  Nail v. Publix Super Markets, Inc., 72 So.3d 608, 616 (Ala. 2011) (“the pharmacist does not have a duty to warn customers of the hazardous side effects either orally or by way of the manufacturer’s package insert”; but finding an exception); Springhill Hospitals, Inc. v. Larrimore, 5 So.3d 513, 518 (Ala. 2008) (“The learned-intermediary doctrine is more than just a narrow rule of law regarding a manufacturer’s or pharmacist’s limited duty to warn.  It addresses questions of liability in light of the relationships between the parties involved in the distribution, prescribing, and use of prescription drugs.”); Walls v. Alpharma USPD, 887 So.2d 881, 886 (Ala. 2004) (“The learned-intermediary doctrine forecloses any duty upon a pharmacist filling a physician’s prescription, valid and regular on its face, to warn the physician’s patient, the pharmacist’s customer, or any other ultimate consumer of the risks or potential side effects of the prescribed medication”).

The only thing we haven’t found in Alabama is a biologic case involving the learned intermediary rule.

Alaska

In Shanks v. Upjohn Co., 835 P.2d 1189 (Alaska 1992), the Alaska Supreme Court followed the learned intermediary rule.  “In determining the adequacy of the warnings and directions in the context of typical prescription drugs, it is appropriate for the trier of fact to consider that the warnings and directions were directed to the prescribing physician rather than to the patient.”  Id. at 1200 & n.17.  We have not seen any Alaska law precedent involving application of the learned intermediary rule in the context of medical devices, biologics, or pharmacists.

Arizona

Arizona adopted the learned intermediary rule in Watts v. Medicis Pharmaceutical Corp., 365 P.3d 944 (Ariz. 2016), a prescription drug case.  “In our view, the Third Restatement properly states the [learned intermediary rule], and therefore we adopt §6(d) as our expression of it.”  Id. at 949.  Conklin v. Medtronic, Inc., 431 P.3d 571 (Ariz. 2018), extended the learned intermediary rule to manufacturers of medical devices – pointing out that the Third Restatement version of the learned intermediary rule expressly applied to both drugs and medical devices.  Id. at 577.

In Lasley v. Shrake’s Country Club Pharmacy, Inc., 880 P.2d 1129 (Ariz. App. 1994), the court rejected the learned intermediary rule in a pharmacy context, but for an unusual reason – “us[ing] details of the standard of conduct to determine whether a duty exists.”  Id. at 1134.  Whether Lasley survives Watts and Conklin is questionable, but undecided.

No Arizona case that we know of has applied learned intermediary rule in litigation involving a biologic.

Arkansas

In West v. Searle & Co., 806 S.W.2d 608, 613 (Ark. 1991), the Arkansas Supreme Court adopted the learned intermediary rule in a prescription drug case.  The rule was “almost universally applied” and “provides that a drug manufacturer may rely on the prescribing physician to warn the ultimate consumer of the risks of a prescription drug.”  Id. at 613.  In Kowalski v. Rose Drugs of Dardanelle, Inc., 378 S.W.3d 109, 120 (Ark. 2011), that court extended the rule to pharmacists:

[W]e believe the more reasoned analysis is that followed by the majority of jurisdictions that there is no general duty to warn, counsel, or refuse to fill prescriptions. . . .  The relationship between the physician-patient-manufacturer applies equally to the relationship between the physician-patient and pharmacist.  In both circumstances the patient must look to the physician.

Id. at 120 (citation and quotation marks omitted).

There is no appellate precedent, but Arkansas federal courts have repeatedly utilized the learned intermediary rule in medical device cases.  Meade v. Ethicon, Inc., 2021 WL 4302252, at *3 (E.D. Ark. Sept. 21, 2021); Kendrick v. Wright Medical Technology, Inc., 2021 WL 3516663, at *6 (E.D. Ark. Aug. 10, 2021) (agreeing that the learned intermediary rule “is just as applicable to medical devices” as it is to drugs); Wilichowski v. Boston Scientific Corp., 2021 WL 798869, at *3 (W.D. Ark. March 2, 2021); Sharp v. Ethicon, Inc., 2020 WL 1434566, at *3 (W.D. Ark. March 24, 2020).

We are unaware of any Arkansas learned intermediary rule biologic cases.

California

California is another state where it is not necessary to go beyond the state’s highest court.  The California Supreme Court first recognized the learned intermediary rule in Stevens v. Parke, Davis & Co., 507 P.2d 653 (Cal. 1973), a prescription drug case.  Id. at 661 (“In the case of medical prescriptions, if adequate warning of potential dangers of a drug has been given to doctors, there is no duty by the drug manufacturer to insure that the warning reaches the doctor’s patient for whom the drug is prescribed.”) (citation and quotation marks omitted).  “[I]n the case of prescription drugs, the duty to warn runs to the physician, not to the patient.”  Carlin v. Superior Court, 920 P.2d 1347, 1354 (Cal. 1996) (emphasis original) (citations omitted).  Thus, “[i]t is well established that a manufacturer fulfills its duty to warn if it provides adequate warning to the physician.”  Brown v. Superior Court, 751 P.2d 470, 477 n.9 (Cal. 1988).  See also T.H. v. Novartis Pharmaceuticals Corp., 407 P.3d 18, 28 (Cal. 2017) (“In the context of prescription drugs, a manufacturer’s duty is to warn physicians about the risks known or reasonably known to the manufacturer.”) (paraphrasing Carlin).

Himes v. Somatics, LLC, 549 P.3d 916, 922-25 (Cal. 2024), explicitly recognized the learned intermediary rule as extending to medical devices as well.

As long as the manufacturer has adequately warned the patient’s physician of the non-negligible risks of its prescription drug or medical device, the manufacturer has fulfilled its duty to warn. . . .  The learned intermediary doctrine recognizes that, while the ordinary consumer may have a reasonable expectation that a product such as a machine . . . will operate safely when used as intended, a patient’s expectations regarding the effects of a prescription drug or medical device are those related . . . by [the] physician, to whom the manufacturer directs the warnings regarding the drug’s or medical device’s properties.

Id. at 923 (citations and quotation marks omitted).  Furthermore, Himes did so in a case that did not involve an implant, but instead “electroconvulsive therapy” device, id. at 921, thereby establishing that the rule is not limited to implants.

California’s adoption of the learned intermediary rule was also noted in Webb v. Special Electric Co., 370 P.3d 1022, 1034 n.10 (Cal. 2016), a non-prescription medical product case.

In Murphy v. E.R. Squibb & Sons, Inc., 710 P.2d 247, 250-53 (Cal. 1985), the same court exempted pharmacists from duty to warn liability, but without specifically mentioning the rule.  Murphy has been recognized as an application of the learned intermediary rule.  E.g., Lacesa v. Walgreen Co., 2022 WL 19240778, at *2 (C.D. Cal. Sept. 22, 2022).

Precedent also applies the learned intermediary rule to biologics in California law cases.  Plummer v. Lederle Laboratories, 819 F.2d 349, 356-57 (2d Cir. 1987) (applying California law); Garcia v. Sanofi Pasteur Inc., 2023 WL 6387171, at *5 (E.D. Cal. Sept. 29, 2023); In re Zostavax Zoster Vaccine Live Products Liability Litigation, 2023 WL 2562981, at *2 (E.D. Pa. March 16, 2023) (applying California law); Colbath v. Merck & Co., 2022 WL 935195, at *6 (S.D. Cal. March 29, 2022) (vaccine); In re Zoster, 2021 WL 3423361, at *5 (E.D. Pa. Aug. 4, 2021) (applying California law).

Colorado

Colorado is one of four remaining states where an intermediate appellate court, but not the state’s high court, has followed the learned intermediary rule.  Hamilton v. Hardy, 549 P.2d 1099, 1110 (Colo. App. 1976), held that “the drug manufacturer’s duty, owed to the public, is the duty to warn the medical profession” (footnote omitted), overruled on other grounds, State Board of Medical Examiners v. McCroskey, 880 P.2d 1188 (Colo. 1994).  A quarter century later, the same court held that the learned intermediary rule also applied in medical device cases.

[T]he learned intermediary rule is generally accepted, and . . . a manufacturer “fulfills its legal obligation to warn by providing adequate warnings to the health-care provider.  Courts in other jurisdictions have applied the learned intermediary doctrine in cases involving medical devices.  Based on the above authorities, we are persuaded that the learned intermediary doctrine should apply to failure to warn claims in the context of a medical device installed operatively when it is available only to physicians and obtained by prescription, and the doctor is in a position to reduce the risks of harm in accordance with the instructions or warnings.

O’Connell v. Biomet, Inc., 250 P.3d 1278,1281-82 (Colo. App. 2010) (citations and quotation marks omitted).  No Colorado decision has addressed the application of the learned intermediary rule to pharmacies, however language in Thornton v. DaVita Healthcare Partners, Inc., 2014 WL 1389958 (D. Colo. April 9, 2014) (citing pharmacy case from Arkansas), recognizes that it does elsewhere.

We have not found a learned intermediary rule case about a biologic under Colorado law.

Connecticut

In Vitanza v. Upjohn Co., 778 A.2d 829, 836-38 (Conn. 2001), the Connecticut Supreme Court adopted the learned intermediary rule in a prescription drug case.

The learned intermediary doctrine provides that adequate warnings to prescribing physicians obviate the need for manufacturers of prescription products to warn ultimate consumers directly. The doctrine is based on the principle that prescribing physicians act as “learned intermediaries” between a manufacturer and consumer and, therefore, stand in the best position to evaluate a patient’s needs and assess the risks and benefits of a particular course of treatment.

Id. at 836-37 (citation and quotation marks omitted).  The learned intermediary rule was extended to medical devices in the Hurley litigation.  Hurley v. Heart Physicians, P.C., 898 A.2d 777, 783-84 (Conn. 2006) (“Although we adopted the learned intermediary doctrine in the context of prescription drugs [in Vitanza], we did not decide whether the policies behind the rule equally were applicable to prescription medical device cases. Numerous courts have determined that they are applicable to prescription medical device cases.”) (citations and footnote omitted); Hurley v. Heart Physicians, P.C., 3 A.3d 892, 900 (Conn. 2010) (“we would agree with the defendant that the trial court properly rendered judgment in its favor on the learned intermediary doctrine”).

A combination of state and federal trial courts has applied the learned intermediary rule to pharmacists.  DiVincenzo v. Molinaro, 2022 WL 17102332, at *3 (Conn. Super. Nov. 2, 2022); Levesque v. Cluett, 2007 WL 4305676, at *3 (Conn. Super. Oct. 16, 2007); Deed v. Walgreen Co., 927 A.2d 1001, 1003-04 (Conn. Super. 2007); Plante v. Lomibiao, 2005 WL 1090180, at *3-4 (Conn. Super. March 31, 2005); Deed v. Walgreen Co., 2004 WL 2943271, at *5 (Conn. Super. Nov. 15, 2004); White v. Stop & Shop Cos., 1998 WL 559730, at *2 (D. Conn. Aug. 17, 1998).

Delaware

In Lacy v. G.D. Searle & Co., 567 A.2d 398 (Del. 1989), the Delaware Supreme Court adopted the learned intermediary rule in a case involving an intrauterine device, and held that the rule applied to both prescription drugs and medical devices.

We hold that it was appropriate . . . to apply the theory of the learned intermediary in this case.  A patient obviously is unable to obtain a prescription drug (or a device of this type) unless his physician orders it.  When a patient consults with a physician seeking a prescription drug or restricted device, the patient also expects the physician to use his informed independent judgment to advise the patient and to prescribe the most appropriate use of the drug or device, based on his professional judgment.  In the final analysis it is the physician who ultimately prescribes the drug or device.  Thus, if the manufacturer of prescription products provides the physician with the legally appropriate information, it has satisfied its duty to warn.

Id. at 400 (emphasis added).

Numerous state and federal trial courts have applied the Delaware learned intermediary rule to both drugs and devices.  Godreau-Rivera v. Coloplast Corp., 598 F. Supp.3d 196, 216-17 (D. Del. 2022) (device); Evans v. Johnson & Johnson Co., 2020 WL 616575, at *4 (D. Del. Feb. 10, 2020) (drug); Green v. Janssen Pharmaceuticals, Inc., 2019 WL 1567841, at *2 (D. Del. April 11, 2019) (drug); Hopkins v. Janssen Pharmaceuticals, Inc., 2019 WL 1567840, at *3 (D. Del. April 11, 2019) (drug); Trower v. Janssen Pharmaceuticals, Inc., 2019 WL 1571834, at *4 (D. Del. April 11, 2019) (drug); Guinan v. A.I. Dupont Hospital for Children, 597 F. Supp.2d 485, 497-98 (E.D. Pa. 2009) (investigational device), rev’d on other grounds, 393 F. Appx. 884 (3d Cir. 2010); Boros v. Pfizer, Inc., 2019 WL 1558576, at *3 (Del. Super. March 25, 2019) (drug); Barba v. Carlson, 2014 WL 1678246, at *2 (Del. Super. April 8, 2014) (device); Crookshank v. Bayer Healthcare Pharmaceuticals, 2009 WL 1622828, at *3 (Del. Super. May 22, 2009) (device); O’Brien-Hastings v. Howmedica Corp., 1996 WL 944855, at *4 (Del. Super. May 15, 1996) (device).

We have not seen any Delaware law learned intermediary decisions concerning pharmacists or biologics.

District of Columbia

In the District of Columbia, Mampe v. Ayerst Laboratories, 548 A.2d 798 (D.C. 1988), recognized that in prescription drug cases, “the user” is “the prescribing physician.”  Id. at 801.  “When the purchase of the product is recommended or prescribed by an intermediary who is a professional, the adequacy of the instructions must be judged in relationship to that professional.”  Id. at 802 n.6 (citation and quotation marks omitted).  The rule’s applicability to medical devices was recognized in Kubicki v. Medtronic, Inc., 293 F. Supp.3d 129, 188-89 (D.D.C. 2018).

[T]he learned intermediary doctrine . . . holds that, because prescription devices are available to the public only through a physician and are to be administered only under a physician’s supervision, the device manufacturer’s duty is to adequately inform the physician, who is expected to function as a “learned intermediary” between the company and the patient in protecting the patient and providing direct information about the device to the patient.

Id. at 188 (citation and quotation marks omitted).

The learned intermediary rule has also been applied in D.C. pharmacy cases.  Ealy v. Richardson-Merrell, Inc., 1987 WL 159970, at *2-3 (D.D.C. Jan. 12, 1987) (following Raynor); Raynor v. Richardson-Merrell, Inc., 643 F. Supp. 238, 246-47 (D.D.C. 1986) (refusing “to impose a duty to warn on pharmacies,” because “such a duty would, in effect, require a pharmacy to substitute its judgment for that of the prescribing physician”).

We are unaware of a biologic learned intermediary rule decision under DC law.

Florida

The Florida Supreme Court has repeatedly followed the learned intermediary rule, beginning with Felix v. Hoffmann-LaRoche, Inc., 540 So.2d 102, 104 (Fla. 1989).

[I]t is clear that the manufacturer’s duty to warn of [the drug’s] dangerous side effects was directed to the physician rather than the patient.  This is so because the prescribing physician, acting as a “learned intermediary” between the manufacturer and the consumer, weighs the potential benefits against the dangers in deciding whether to recommend the drug to meet the patient’s needs.

Id. at 104 (citation omitted).  Accord Upjohn Co. v. MacMurdo, 562 So. 2d 680, 683 (Fla. 1990) (“The manufacturer’s duty to warn of the drug’s dangerous side effects is directed to the physician rather than the patient.”) (citation omitted).

In E.R. Squibb & Sons, Inc. v. Farnes, 697 So.2d 825, 827 (Fla. 1997), the court affirmed application of the learned intermediary rule in the vaccine (biologics) context.  Accord Guarino v. Wyeth, LLC, 719 F.3d 1245, 1250 (11th Cir. 2013) (“Pharmaceutical manufacturers discharge their duty to warn the learned intermediary by way of a package insert which accompanies each vial of vaccine.”) (citation and quotation marks omitted); Christopher v. Cutter Laboratories, 53 F.3d 1184, 1192-93 (11th Cir. 1995) (also applying learned intermediary rule in biologic case).

While the Florida Supreme Court has not addressed the learned intermediary rule in a medical device case, other appellate courts, both federal and state have applied it.  Cavanaugh v. Stryker Corp., 308 So.3d 149 (Fla. App. 2020), held:

Even assuming that some version of the consumer expectations test should apply to complex medical products which are provided to a consumer through a learned intermediary, the standard instruction would need to be modified in order to inform the jury that the relevant expectations are those of the health care professional.  The Plaintiff’s proposed instruction as written would have been misleading to the jury because it failed to inform the jury that the relevant expectations are those of the medical professional, not the ordinary consumer.

Id. at 156 (citations omitted).  The Eleventh Circuit has agreed:

[I]n cases involving medical products . . . the duty of a device manufacturer to warn of dangers involved in the use of a device is satisfied if it gives adequate warning to the physician who prescribes the device.  The physician acts as a “learned intermediary” between the manufacturer and the patient, weighing the potential benefits of a device against the dangers in deciding whether to recommend it to meet the patient’s needs.  Thus, in order to satisfy the causation requirement in a medical device failure-to-warn claim, a plaintiff must show that her treating physician would not have used the product had adequate warnings been provided.  The learned intermediary doctrine is a longstanding feature of Florida law.

Salinero v. Johnson & Johnson, 995 F.3d 959, 964-65 (11th Cir. 2021) (citations and quotation marks omitted).  Accord Cates v. Zeltiq Aesthetics, Inc., 73 F.4th 1342, 1347 (11th Cir. 2023) (“We must first address whom a product manufacturer must warn.  In cases involving medical devices . . ., the device manufacturer has a duty to warn the physician who prescribes the device.) (citation and quotation marks omitted); Eghnayem v. Boston Scientific Corp., 873 F.3d 1304, 1321 (11th Cir. 2017) (“For medical products like [this device], the duty to warn is directed to physicians rather than patients under the ‘learned intermediary’ doctrine.”) (citation omitted); Mink v. Smith & Nephew, Inc., 860 F.3d 1319, 1330 (11th Cir. 2017) (“[Defendant’s] duty . . . if any, was to the physician, not [plaintiff].  We therefore affirm . . . dismissal of [plaintiff’s] negligence claim to the extent it was premised on an improper training theory.”) (citation omitted).  In addition, Beale v. Biomet, Inc., 492 F. Supp.2d 1360, 1367-68 (S.D. Fla. 2007), has been particularly influential in the medical device context.

In McLeod v. M.S. Merrell Co., 174 So.2d 736, 738-39 (Fla. 1965), the Florida high court also exempted pharmacists from duty to warn liability, but without specifically mentioning the rule.  Another Florida case reaching the same result is Estate of Johnson v. Badger Acquisition of Tampa LLC, 983 So.2d 1175, 1186 n.4 (Fla. App. 2008) (“imposing a duty to warn on the pharmacist would intrude on the doctor-patient relationship and would force the pharmacist to practice medicine without a license”) (citation and quotation marks omitted).

Georgia

In McCombs v. Synthes (U.S.A.), 587 S.E.2d 594 (Ga. 2003), the Georgia Supreme Court recognized the learned intermediary rule in a medical device case, and also held that it applied to prescription drugs.

Under the learned intermediary doctrine, the manufacturer of a prescription drug or medical device does not have a duty to warn the patient of the dangers involved with the product, but instead has a duty to warn the patient’s doctor, who acts as a learned intermediary between the patient and the manufacturer.  The rationale for the doctrine is that the treating physician is in a better position to warn the patient than the manufacturer, in that the decision to employ prescription medication or medical devices involves professional assessment of medical risks in light of the physician’s knowledge of a patient’s particular need and susceptibilities.

Id. at 595 (footnotes and quotation marks omitted).  See In re Bard IVC Filters Products Liability Litigation, 969 F.3d 1067, 1076 (9th Cir. 2020) (quoting and following McCombs) (applying Georgia law).

Georgia appellate courts have also barred claims against pharmacists.  Nail v. State, 686 S.E.2d 483, 485-86 (Ga. App. 2009) (quoting and following Chamblin); Chamblin v. K-Mart Corp., 612 S.E.2d 25, 28 (Ga. App. 2005) (McCombs’ “reasoning that the treating physician is in a better position to warn a patient of the dangers associated with a drug or medical device would seem to apply in the case of a pharmacist as well”).

We have not seen a Georgia biologic case involving the learned intermediary rule.

Hawai’i

Similarly to Georgia, the Hawai’i Supreme Court adopted the learned intermediary rule in a medical device (breast implant) case.

The learned intermediary rule assumes that it is reasonable for a manufacturer to rely on the prescribing physician to forward to the patient, who is the ultimate user of the drug products, any warnings regarding their possible side effects.  The rule does not alter the duty of a manufacturer to provide adequate warnings rather, the doctrine simply substitutes the physician for the consumer as the person to receive those warnings.  Because the manufacturer has little or no contact with the ultimate consumer and the treating physician makes the purchasing decisions and judgments concerning medical products, the warnings are better conveyed to the physician user.

Craft v. Peebles, 893 P.2d 138, 155 (Haw. 1995) (citations and quotation marks omitted).  Of course, Hawai’i courts have applied the learned intermediary rule in prescription drug cases as well.  Evans v. Gilead Sciences, Inc., 2020 WL 5189995, at *12 (D. Haw. Aug. 31, 2020) (“Hawai’i adheres to the ‘learned intermediary’ rule in the the prescription drug arena.”) (citation and quotation marks omitted); Forsyth v. Eli Lilly & Co., 1998 WL 35152135, at *6 (D. Haw. Jan. 5, 1998) (“a drug manufacturer can presume that its warnings will be passed on from the prescribing physician to the ultimate patient/consumer under the ‘learned intermediary’ doctrine”) (citation omitted); Yamane v. Wyeth, 2012 WL 1120367 ¶23 (Haw. Cir. Jan. 3, 2012) (“conclud[ing] that plaintiffs’ state-law tort claims are also barred as a matter of law by the learned intermediary doctrine”).

We were unable to find any biologic or pharmacy liability cases out of Hawai’i.

Idaho

Idaho is an odd duck.  Idaho’s highest court has adopted the learned intermediary rule, but not in the prescription medical product context.

[I]n some circumstances a supplier positioned on the commercial chain remote from the ultimate consumer may fulfill its duty to warn by adequately warning an intermediary. . . .  [T]he first [of these] being when a drug manufacturer properly warns a prescribing physician of the dangerous propensities of its product.  The doctor stands as a learned intermediary between the manufacturer and the ultimate consumer. Generally, only the doctor could understand the propensities and dangers involved in the use of a given drug.

Sliman v. Aluminum Co. of America, 731 P.2d 1267, 1270 (Idaho 1986) (citations and quotation marks omitted).

An early vaccine/biologic case under Idaho law held, “[o]rdinarily in the case of prescription drugs warning to the prescribing physician is sufficient,” but created an exception for mass immunizations.  Davis v. Wyeth Laboratories, Inc., 399 F.2d 121, 130-31 (9th Cir. 1968).  The only other learned intermediary rule decision under Idaho law is a medical device decision, In re Zimmer M/L Taper Hip Prosthesis or M/L Taper Hip Prosthesis with Kinectiv Technology & Versys Femoral Head Products Liability Litigation, 2021 WL 3475681, at *11 (S.D.N.Y. Aug. 6, 2021) (“the learned intermediary doctrine applies, so that [defendant’s] duty to warn ran to [the] surgeon”), reconsideration denied, 2021 WL 4251906 (S.D.N.Y. Sept. 17, 2021) (applying Idaho law).

No Idaho law pharmacy learned intermediary rule cases turned up.

Illinois

Illinois, by contrast, has a plethora of learned intermediary rule precedent.  The Illinois Supreme Court first followed the rule in Kirk v. Michael Reese Hospital & Medical Center, 513 N.E.2d 387 (Ill. 1987), involving prescription drugs:

[A]dequate warnings are to be given to physicians only and not to the public generally. . . .  The rule, as adopted in numerous jurisdictions, provides that manufacturers of prescription drugs have a duty to warn prescribing physicians of the drugs’ known dangerous propensities, and the physicians, in turn, using their medical judgment, have a duty to convey the warnings to their patients.  We cannot quarrel with the general proposition that where prescription drugs are concerned, the manufacturer’s duty to warn is limited to an obligation to advise the prescribing physician of any potential dangers that may result from the drug’s use. . . .  The doctor, functioning as a learned intermediary between the prescription drug manufacturer and the patient, decides which available drug best fits the patient’s needs and chooses which facts from the various warnings should be conveyed to the patient, and the extent of disclosure is a matter of medical judgment.  As such, we believe the learned intermediary doctrine is applicable here and that there is no duty on the part of manufacturers of prescription drugs to directly warn patients.

Id. at 392-93 (citations and quotation marks omitted).  Accord Martin v. Ortho Pharmaceutical Corp., 661 N.E.2d 352, 356 (Ill. 1996) (“We agree with those decisions which have declined to recognize an exception to the learned intermediary doctrine for manufacturers of contraceptive pharmaceuticals.”)

The Illinois high court applied the learned intermediary rule in the medical device context in Hansen v. Baxter Healthcare Corp., 764 N.E.2d 35 (Ill. 2002):

Generally, the manufacturer of a prescription medical device has a duty to warn prescribing physicians or other health professionals who may prescribe the device of the product’s known dangerous propensities.  Likewise, physicians, using their medical judgment, have a duty to convey the warnings to their patients.  The duty to warn the health-care professional, rather than the ultimate consumer or patient, is an expression of the “learned intermediary” doctrine.

Id. at 42.

The Illinois Supreme Court has likewise recognized that the learned intermediary rule precludes pharmacists from owing generalized warning duties:

[W]e think that it is unreasonable to argue that by placing only the [one] label on the prescription container, a pharmacist might mislead a consumer into believing that [the labeled risk] is the only side effect of [the drug].  In our opinion, consumers should principally look to their prescribing physician to convey the appropriate warnings regarding drugs, and it is the prescribing physician’s duty to convey these warnings to patients.

Frye v. Medicare-Glaser Corp., 605 N.E.2d 557, 561 (Ill. 1992) (citation omitted).  See also Happel v. Wal-Mart Stores, Inc., 766 N.E.2d 1118, 1127 (Ill. 2002) (“[P]harmacists should not have a duty to warn a patient or physician of the adverse side effects of prescription drugs [because i]mposing such a duty . . . would require the pharmacist to learn the customer’s condition and monitor his drug usage. To accomplish this, the pharmacist would have to interject himself into the doctor-patient relationship and practice medicine without a license.”).  Indeed, the Seventh Circuit considered pharmacy non-liability so well established in Illinois that it held joining pharmacies to be fraudulent joinder.  Walton v. Bayer Corp., 643 F.3d 994, 1001 (7th Cir. 2011).

The learned intermediary rule was applied to a biologic in Tongate v. Wyeth Laboratories, 580 N.E.2d 1220, 1224-55 (Ill. App. 1991).  Accord Mohr v. Targeted Genetics, Inc., 690 F. Supp.2d 711, 719-20 (C.D. Ill. 2010); Erickson v. Baxter Healthcare, Inc., 151 F. Supp.2d 952, 962 (N.D. Ill. 2001).

Indiana

Indiana is another state, like Colorado, where the learned intermediary rule has been adopted by the state’s intermediate appellate court.  That first happened in a decision involving a prescription contraceptive drug.  An “important limitation on liability in [the prescription drug] context . . . applies to manufacturers of ethical drugs.  Since such drugs are available only by prescription, a manufacturers duty to warn extends only to the medical profession, and not the ultimate users.”  Ortho Pharmaceutical Corp. v. Chapman, 388 N.E.2d 541, 548 (Ind. App. 1979) (citations and footnote omitted).  See also Ziliak v. AstraZeneca LP, 324 F.3d 518, 521 (7th Cir. 2003) (defendant “is absolved of strict liability so long as it has imparted adequate warnings to treating physicians”) (citation omitted).

Several intermediate Indiana appellate decisions have since recognized the rule’s applicability in pharmacy liability cases.  Ingram v. Hook’s Drugs, Inc., 476 N.E.2d 881 (Ind. App. 1985), held:

[T]he duty to warn of hazards associated with prescription drugs is part and parcel of the physician-patient relationship. . . .  The decision of weighing the benefits of a medication against potential dangers that are associated with it requires an individualized medical judgment.  This individualized treatment is available in the context of a physician-patient relationship which has the benefits of medical history and extensive medical examinations.  It is not present, however, in the context of a pharmacist filling a prescription for a retail customer.  The injection of a third-party in the form of a pharmacist into the physician-patient relationship could undercut the effectiveness of the ongoing medical treatment.  We perceive the better rule to be one which places the duty to warn of the hazards of the drug on the prescribing physician and requires of the pharmacist only that he include those warnings found in the prescription.

Id. at 886-87 (“concur[ing]” with Chapman).  Accord Allberry v. Parkmor Drug, Inc., 834 N.E.2d 199, 202 (Ind. App. 2005) (“imposing such a [warning] duty on the pharmacist would place the pharmacist between the physician − who knows the patient’s physical condition − and the patient and could lead to harmful interference in the patient-physician relationship”); Peters v. Judd Drugs, Inc., 602 N.E.2d 162, 165 (Ind. App. 1992) (“a pharmacist had no duty to warn a consumer of the possible side effects of a prescription drug prescribed by a physician”).

Oddly, there is no Indiana state appellate precedent applying the learned intermediary rule in the medical device context.  Federal appellate authority fills this gap.  Kaiser v. Johnson & Johnson, 947 F.3d 996, 1015 (7th Cir. 2020) (“Under Indiana’s learned-intermediary doctrine, a medical-device manufacturer can discharge this duty by providing adequate warnings to physicians.”); Phelps v. Sherwood Medical Industries, 836 F.2d 296, 303 (7th Cir. 1987) (“This ‘learned intermediary’ exception has equal application to those cases concerning medical devices.”).  See Hammons v. Ethicon, Inc., 190 A.3d 1248, 1270 (Pa. Super. 2018) (“Indiana follows the learned intermediary doctrine, under which [defendant’s] duty to warn for a prescription-only product like [this device] ‘extends only to the medical profession, and not the ultimate users.’”) (quoting Chapman), aff’d, 240 A.3d 537 (Pa. 2020) (applying Indiana law).

The only cases applying the Indiana learned intermediary rule to biologics are outside Indiana.  See Juday v. Sadaka, 2023 WL 6520487, at *2 (E.D. Pa. Oct. 5, 2023) (“Under Indiana law, the learned intermediary doctrine applies to this claim.”); Cleary v. Biogen, Inc., 2017 WL 8226624, at *8-12 (Mass. Super. Sept. 8, 2017) (“The learned intermediary doctrine applies to failure to warn claims in Indiana.”) (citation omitted).

Iowa

While the Iowa Supreme Court never directly addressed the learned intermediary rule, it “recognize[d]” the rule as an example of a “‘no duty’ rule[] in the warning area based on . . . lack of control” in McCormick v. Nikkel & Associates, Inc., 819 N.W.2d 368, 375 (Iowa 2012).

The only Iowa law decisions directly applying the learned intermediary rule in prescription medical product liability litigation are federal.  Petty v. United States, 740 F.2d 1428 (8th Cir. 1984), applied the rule – and its mass-immunization exception − in a vaccine (biologic) case.  “[I]n a mass immunization context, where there is no learned intermediary, the duty extends to the ultimate recipient of the vaccine.”  Id. at 1440.

Several federal district court decisions have applied the rule.  Kelly v. Ethicon, Inc., 2020 WL 6120155, at *7 (N.D. Iowa Oct. 16, 2020) (following Willet; medical device case), reconsideration denied, 2021 WL 7185090 (N.D. Iowa, March 9, 2021); Kelly v. Ethicon, Inc., 2020 WL 4572348, at *4 (N.D. Iowa Aug. 7, 2020) (“Under the learned intermediary doctrine, a manufacturer of prescription drug or medical device need not provide warnings directly to patients using its products so long as adequate warnings were given to the health care provider supplying the products to patients.”) (citations omitted); Wessels v. Biomet Orthopedics, 2020 WL 3421478, at *14 (N.D. Iowa June 22, 2020) (“Under [the learned intermediary] rule, [defendant] need only have adequately warned [the implanter] about the risks of the [medical device], not [plaintiff] himself.”); Nicholson v. Biomet, Inc., 2020 WL 3399899, at *19 (N.D. Iowa March 6, 2020) (citing McCormick and Petty medical device case); Willet v. Johnson & Johnson, 2019 WL 7500524, at *2 (S.D. Iowa Sept. 30, 2019) (“in the context of prescription medical devices and drugs, Iowa follows the learned intermediary doctrine”); Gilliland v. Novartis Pharmaceuticals Corp., 34 F. Supp.3d 960, 969 (S.D. Iowa 2014) (“manufacturers of prescription drugs discharge their duty of care to patients by warning the health-care providers who prescribe and use the drugs to treat them”); Madsen v. American Home Products Corp., 477 F. Supp.2d 1025, 1033-34 (E.D. Mo. 2007) (“the Court believes that Iowa would adopt the doctrine”) (citing Petty) (applying Iowa law); Doe v. Baxter Healthcare Corp., 2003 WL 27384538, at *4 (S.D. Iowa June 3, 2003) (the learned intermediary rule “has been recognized by the Eighth Circuit, applying Iowa law”; biologic case) (following Petty), aff’d, 380 F.3d 399 (8th Cir. 2004).

We don’t know of any pharmacist cases from Iowa.

Kansas

In Wooderson v. Ortho Pharmaceutical Corp., 681 P.2d 1038, 1052 (Kan. 1984), the Kansas Supreme Court “conclude[d]” that the defendant “had a duty to warn the prescribing physician” and “h[e]ld that the manufacturer of an ethical drug has a duty to warn the medical profession of dangerous side effects of its products.”  Id. at 1057.  Wooderson did so after a lengthy discussion of learned intermediary cases from other jurisdictions.  Id. at 1049-56.  Accord Humes v. Clinton, 792 P.2d 1032, 1042-43 (Kan. 1990) (“under the learned intermediary rule drug manufacturers are not liable for failure to directly warn patients of risks and side effects”); Savina v. Sterling Drug, Inc., 795 P.2d 915, 929 (Kan. 1990) (“This case involves an individualized medical decision and the learned intermediary rule applies.”) (prescription drug case).

In Johnson v. American Cyanamid Co., 718 P.2d 1318 (Kan. 1986), the court extended the rule to vaccines/biologics:

As in the case before us, the drug in Wooderson was sold to a physician who, in turn, prescribed/administered the drug to the patient.  As recognized in Wooderson, under such circumstances the “learned intermediary” concept comes into play. The manufacturer’s duty is to adequately warn the physician of a known risk.

Id. at 1324.

Also, in Tetuan v. A.H. Robins Co., 738 P.2d 1210 (Kan. 1987), the court applied the learned intermediary rule to a medical device.  Such devices “are ethical products − that is, they are available only through licensed medical care providers.”  Id. at 1227.

[T]he patient is expected to look to the physician for guidance and not to the manufacturer of the products which he may use or prescribe in the course of treatment.  We apply that same rationale to plaintiff’s action for fraud . . ., and we hold that, where a patient relies on a physician for treatment or advice as to an ethical or prescription device, justifiable reliance by the physician . . . constitutes justifiable reliance by the patient.

Id. at 1228 (citation and quotation marks omitted).  Accord Ralston v. Smith & Nephew Richards, Inc., 275 F.3d 965, 974-75 (10th Cir. 2001) (applying learned intermediary rule in medical device case).

In Nichols v. Central Merchandise, 817 P.2d 1131, 1133 (Kan. App. 1991), the court barred pharmacist claims.  Id. at 1133 (“because the doctor is the learned intermediary between the manufacturer and the patient, the patient should rely on the doctor; the pharmacist . . . has no legal duty to warn the patient of potential consequences from the use of the drug prescribed by the doctor”).

Kentucky

The Kentucky Supreme Court adopted the learned intermediary rule in Larkin v. Pfizer, Inc., 153 S.W.3d 758 (Ky. 2004), answering a certified question “yes.”  Id. at 761.  “Although the rule largely applies to prescription drugs, some courts have extended it to cases involving prescription medical implants and devices.”  Id. (citations omitted).  Larkin comprehensively discussed the rationales supporting the rule.  Id. at 763-64.  See Hyman & Armstrong, P.S.C. v. Gunderson, 279 S.W.3d 93, 109 (Ky. 2008) (in Larkin “we adopted the learned intermediary doctrine”).  The Sixth Circuit, applying Kentucky law, has also applied the learned intermediary rule to medical devices.  Thacker v. Ethicon, Inc., 47 F.4th 451, 460 (6th Cir. 2022) (“[i]n medical device cases, Kentucky applies the learned intermediary rule”).  In Snawder v. Cohen, 749 F. Supp. 1473, 1480 (W.D. Ky. 1990), the learned intermediary rule applied to a biologic.  A Kentucky federal court has also barred pharmacist claims under the rule.  Foister v. Purdue Pharma, L.P., 295 F. Supp.2d 693, 706 (E.D. Ky. 2003) (“The learned intermediary doctrine provides that once a drug manufacturer has warned physicians of the dangers of the drug, the pharmacy’s liability is cut off by the physician’s knowledge.“).

Louisiana

Louisiana intermediate appellate courts have followed the learned intermediary rule consistently, and the Louisiana Supreme Court has never accepted an appeal from any of those decisions.  The first decision was Cobb v. Syntex Laboratories, Inc., 444 So.2d 203 (La. App. 1983), holding:

The manufacturer of a prescription drug has the obligation to inform the prescribing physician of any potentially adverse side effects or risks from the drug’s use. . . .  The manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with the drug.  The manufacturer of the drug has fulfilled its obligation when it has informed the prescribing and treating physicians of the risks of harm from the drug so that they may intelligently decide on its use and advise the patient.  The doctor acts as an informed intermediary.  The decision to use the drug in a particular circumstance rests with the doctor and the patient, not with the manufacturer.

Id. at 205 (citation omitted).  See also Kampmann v. Mason, 921 So.2d 1093, 1094 (La. App. 2006) (“Under the learned intermediary the drug manufacturer has no duty to warn the customer directly. The manufacturer’s duty is fulfilled when the prescribing or treating physician is informed of the risks from the drug use.”) (drug); Marks v. Ohmeda, Inc., 871 So.2d 1148, 1157 (La. App. 2004) (quoting Brown) (medical device); Brown v. Glaxo, Inc., 790 So.2d 35, 38 (La. App. 2000) (“[U]nder the ‘learned intermediary doctrine,’ the doctor acts as an informed intermediary between the drug company and the patient. Thus, a drug manufacturer has a duty to warn the prescribing doctor, rather than the patient, of potential risks associated with the use of the drug.”) (drug); Calhoun v. Hoffman-LaRoche, Inc., 768 So.2d 57, 61 (La. App. 2000) (drug) (quoting Cobb); Mikell v. Hoffman-LaRoche, Inc., 649 So.2d 75, 79 (La. App. 1994) (“[A] drug manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with its product.  The obligation to the consumer is fulfilled when the prescribing or treating physician is informed of any potential side effects or risks”) (drug); Rhoto v. Ribando, 504 So.2d 1119, 1123 (La. App. 1987) (“A drug manufacturer has no duty to warn the consumer directly of any risks or contraindications associated with its product. The obligation to the consumer is fulfilled when the prescribing or treating physician is informed of the risks of harm from the drug.”) (drug); Kinney v. Hutchinson, 468 So.2d 714, 717-18 (La. App. 1985) (drug) (quoting Cobb).

The learned intermediary rule also precludes pharmacy-related warning claims in Louisiana.

The pharmacist does not . . . have a duty to question a judgment made by the physician as to the propriety of a prescription or to warn customers of the hazardous side effects associated with a drug, either orally or by way of the manufacturer’s package insert.

Gassen v. East Jefferson General Hospital, 628 So.2d 256, 259 (La. App. 1993).  See Id. at 258 (“Under both common law and under Louisiana jurisprudence a pharmacist does not have a duty to warn a patient of adverse reactions.”).  Accord Guillory v. Doctor X, 679 So.2d 1004, 1010 (La. App. 1996) (quoting Gassen).

Federal appellate decisions applying Louisiana law routinely follow the learned intermediary rule.

Louisiana applies the “learned intermediary doctrine” to products liability claims involving prescription drugs.  Under this doctrine, a drug manufacturer discharges its duty to consumers by reasonably informing prescribing physicians of the dangers of harm from a drug.

Stahl v. Novartis Pharmaceuticals Corp., 283 F.3d 254, 265 (5th Cir. 2002) (drug) (citation omitted).  Accord In re Taxotere (Docetaxel) Products Liability Litigation, 994 F.3d 704, 708 (5th Cir. 2021) (drug); Grenier v. Medical Engineering Corp., 243 F.3d 200, 205 n.4 (5th Cir. 2001) (medical device); Theriot v. Danek Medical, Inc., 168 F.3d 253, 256 (5th Cir. 1999) (medical device); Willett v. Baxter International, Inc., 929 F.2d 1094, 1098 (5th Cir. 1991) (medical device); Anderson v. McNeilab, Inc., 831 F.2d 92, 93 (5th Cir. 1987) (drug).

We didn’t find a Louisiana biologic learned intermediary rule decision.

Maine

The Maine Supreme Judicial Court has never addressed the learned intermediary rule.  The First Circuit, in Violette v. Smith & Nephew Dyonics, Inc., 62 F.3d 83 (1st Cir. 1995), applied the rule to a medical device case.

While the Supreme Judicial Court of Maine has not decided the matter, the general rule regarding medical devices (and, more frequently and by analogy, prescription drugs) is that the manufacturer must warn the physician − the so-called “learned intermediary” − and not the patient directly.

Id. at 13 (citations omitted).  Accord Doe v. Solvay Pharmaceuticals, Inc., 153 F. Appx. 1, 3 (1st Cir. 2005) (“This court already has decided that Maine courts would adopt that rule”) (citing Violette) (drug), affirming, 350 F. Supp.2d 257, 270-71 (D. Me. 2004).  Accord Novak v. Mentor Worldwide LLC, 287 F. Supp.3d 85, 95-96 (D. Me. 2018) (“a manufacturer fulfills its duty to warn a consumer of the dangers inherent in a product when the manufacturer has adequately warned the consumer’s physician”) (medical device); Herzog v. Arthrocare Corp., 2003 WL 1785795, at *8 (D. Me. March 21, 2003) (medical device).  See also In re Davol, Inc./C.R. Bard, Inc., Polypropylene Hernia Mesh Products Liability Litigation, 2024 WL 363235, at *3 (S.D. Ohio Jan. 31, 2024) (“Under the learned intermediary doctrine, a manufacturer’s duty to warn is fulfilled when the manufacturer has adequately warned the physician, rather than the plaintiff himself.”) (medical device) (applying Maine law); In re Davol, Inc./C.R. Bard, Inc., Polypropylene Hernia Mesh Products Liability Litigation, 2023 WL 2478553, at *12 (S.D. Ohio Jan. 31, 2024) (“This Court finds the reasoning in Tardy and in the numerous federal trial and appellate court decisions applying Maine law to be persuasive.  Therefore, the Court finds that the learned intermediary doctrine should apply in this case.”) (medical device) (applying Maine law).

A Maine trial court applied the learned intermediary rule to bar claims against a pharmacist in Tardy v. Eli Lilly & Co., 2004 WL 1925536 (Me. Super. Aug. 3, 2004).

[H]olding pharmacists liable would not serve as an incentive to safety since the pharmacist presented with a prescription ordered by a duly licensed physician is not at liberty to substitute his or her judgment of the product’s safety for the patient for that of the physician.  Based on the foregoing, the court adopts the majority view and holds that the learned intermediary doctrine applies to the present action.

Id. at *2-3 (citation and quotation marks omitted).

Apparently, no Maine law court has ever addressed the learned intermediary rule in a biologic context.

Maryland

The Maryland Supreme Court applied the learned intermediary rule to pharmacies in Rite Aid Corp. v. Levy-Gray, 894 A.2d 563 (Md. 2006):

[T]he “learned intermediary” doctrine . . . applies to the tripartite relationship between the drug manufacturer, the prescribing physician, and the patient. . . .  As stated by the Restatement (Third) of Torts, “the traditional rules [are] that drug and medical-device manufacturers are liable only when their products contain manufacturing defects or are sold without adequate instructions and warnings to prescribing and other health-care providers”. . . .  The “learned intermediary” doctrine has been extended to provide a defense to pharmacies and pharmacists by the courts of other jurisdictions.

Id. at 577 (citations omitted).  An earlier Maryland decision, Nolan v. Dillon, 276 A.2d 36, 40 (Md. 1971), has been cited (including by us) as applying the learned intermediary rule, but did not do so explicitly.  See Gourdine v. Crews, 955 A.2d 769, 782-83 (Md. 2008).

The Maryland intermediate appellate court in Gourdine applied the learned intermediary rule, which the high court’s subsequent affirmance did not reach:

With respect to prescription drugs, Maryland law recognizes the “learned intermediary” doctrine, which provides that manufacturers need only warn the prescribing physician and not the patient directly.  Stated alternatively, under the learned intermediary doctrine, the manufacturer of a prescription drug has no duty to directly warn patients.

Gourdine v. Crews, 935 A.2d 1146, 1150 (Md. Spec. App. 2007), aff’d on other grounds, 955 A.2d 769 (Md. 2008).  Accord Larson v. Abbott Laboratories, Inc., 2018 WL 3479236, at *9 (Md. Spec. App. July 19, 2018) (“In pharmaceutical failure to warn cases, the ‘learned intermediary’ doctrine provides an exception to a manufacturer’s duty to warn the consumer directly; instead, the duty to warn runs to the prescribing physician.  Therefore, a pharmaceutical manufacturer has a duty to warn physicians or other personnel authorized to prescribe drugs by state law.”) (citations and quotation marks omitted) (biologic).

Federal appellate courts have likewise viewed Maryland as applying the learned intermediary rule in prescription medical product liability litigation.  Doe v. Miles Laboratories, Inc., 927 F.2d 187, 194 (4th Cir. 1991) (“A pharmaceutical manufacturer must warn physicians or other medical personnel authorized to prescribe drugs by state law.”) (biologic); Hofherr v. Dart Industries, Inc., 853 F.2d 259, 263 (4th Cir. 1988) (“Any obligation of [a pharmacist] to the consumer to warn was not to warn the consumer or the franchisee of the prescription drug, rather to warn the physician who prescribed it.”).

Somehow, no appellate case applying Maryland law has had occasion to apply the learned intermediary rule in a medical device case.  Numerous federal district courts have done so.  Here are the published ones:  Morris v. Biomet, Inc., 491 F. Supp.3d 87, 104 (D. Md. 2020); Miller v. Bristol-Myers Squibb Co., 121 F. Supp.2d 831, 838 (D. Md. 2000); Lee v. Baxter Healthcare Corp., 721 F. Supp. 89, 95 (D. Md. 1989), aff’d, 898 F.2d 146 (4th Cir. 1990).

Massachusetts

Massachusetts adopted the learned intermediary rule in MacDonald v. Ortho Pharmaceutical Corp., 475 N.E.2d 65 (Mass. 1985), a prescription drug case.

The rule in jurisdictions that have addressed the question of the extent of a manufacturer’s duty to warn in cases involving prescription drugs is that the prescribing physician acts as a “learned intermediary” between the manufacturer and the patient, and the duty of the ethical drug manufacturer is to warn the doctor, rather than the patient, although the manufacturer is directly liable to the patient for a breach of such duty.

Id. at 68 (citation and quotation marks omitted).

The rule was extended to pharmacists in Cottam v. CVS Pharmacy, 764 N.E.2d 814, 820 (Mass. 2002):

A number of jurisdictions have addressed the issue [of pharmacy duty to warn], and the overwhelming majority hold that, in general, a pharmacy has no duty to warn its customers of side effects.  We similarly hold that, generally, a pharmacy has no duty to warn its customers of the side effects of prescription drugs.

Other jurisdictions have reached this result by extending to pharmacies the “learned intermediary doctrine,” a rule commonly applied to drug manufacturers. . . .   The learned intermediary doctrine in this context provides that a prescription drug manufacturer’s duty to warn of dangers associated with its product runs only to the physician; it is the physician’s duty to warn the ultimate consumer. . . .  

This court has already recognized the learned intermediary doctrine in the context of prescription drug manufacturers.  Because the physician is the appropriate person to perform the duty of warning a patient of the possible side effects of prescription drugs, we now extend this doctrine to pharmacies.

Id. at 819-21 (citations and quotation marks and footnote omitted).

No appellate Massachusetts state court decision has applied the learned intermediary rule in a medical device case.  Numerous federal decisions have done so.  Here are the reported ones.  Plourde v. Sorin Group USA, Inc., 23 F.4th 29, 36 (1st Cir. 2022); Knowlton v. Deseret Medical, Inc., 930 F.2d 116, 120 n.2 (1st Cir. 1991); Corrigan v. Covidien LP, 748 F. Supp.3d 1, 12 (D. Mass. 2024); In re Fresenius GranuFlo/NaturaLyte Dialysate Products Liability Litigation, 691 F. Supp.3d 280, 299 (D. Mass. 2023); Plourde v. Sorin Group USA, Inc., 517 F. Supp.3d 76, 88-89 (D. Mass. 2021); Taupier v. Davol, Inc., 490 F. Supp.3d 430, 447 (D. Mass. 2020); Langlois v. American Medical Systems, Inc., 462 F. Supp.3d 1, 4 (D. Mass. 2020); Mongeon v. Ethicon, Inc., 456 F. Supp.3d 298, 302 (D. Mass. 2020); Lareau v. Page, 840 F. Supp. 920, 933 (D. Mass. 1993), aff’d, 39 F.3d 384 (1st Cir. 1994).

Prescription biologics are also subject to the learned intermediary rule under Massachusetts law.  Calisi v. Abbott Laboratories, 2013 WL 5441355, at *3 (D. Mass. Sept. 27, 2013).

Michigan

In Smith v. E.R. Squibb & Sons, Inc., 273 N.W.2d 476, 479 (Mich. 1979), the Michigan Supreme Court stated, “[a] manufacturer of a prescription drug has a legal duty to warn the medical profession, not the patient, of any risks inherent in the use of the drug which the manufacturer knows or should know to exist.”  Id. at 479 (citations omitted).  That sure looked like a precedential holding, but a later decision of the same court called that “dictum.”  In re Certified Questions, 358 N.W.2d 873, 877 (Mich. 1984).  Nothing further has been decided by the Michigan Supreme Court.

Michigan intermediate appellate decisions have followed the Smith language and applied the learned intermediary rule in a prescription drug case.

[T]he “learned intermediary” doctrine . . . applied to manufacturers of prescription drugs, who are required to warn only the prescribing physician, who acts as a “learned intermediary” between the manufacturer and consumer. . . .  The “learned intermediary” doctrine has been adopted by many other jurisdictions, where it has almost unanimously been applied for all prescription drugs.

Mowery v. Crittenton Hospital, 400 N.W.2d 633, 637 (Mich. App. 1986) (citations omitted).  Accord King-Washington v. Eli Lilly & Co., 394 F. Appx. 827, 828-29 (2d Cir. 2010) (prescription drug) (applying Michigan law).

The rule was applied to medical devices in Brown v. Drake-Willock International, Ltd., 530 N.W.2d 510 (Mich. App. 1995):

[I]n the absence of a clear legal duty imposed on defendant manufacturers to directly warn plaintiffs, plaintiffs have failed to state a claim upon which they may recover. 

We now hold that the reasoning and policy behind the learned intermediary rule applies not only to prescription drugs, but also to prescription devices. . . .  Under the learned intermediary rule, the hospital or physician was the proper recipient of necessary information or warnings, not plaintiff. . . .  [D]efendant manufacturers had no duty to warn plaintiff in this case because of the learned intermediary rule.

Id. at 516 (citations omitted).

Dunn v. Lederle Laboratories, 328 N.W.2d 576, 580-81 (Mich. App. 1982), applied the learned intermediary rule to vaccines/biologics.

Warnings generally must be calculated to reach the ultimate consumer.  An exception exists for drugs dispensed in a manner requiring a physician to weigh the risks and benefits of a drug’s use on a particular patient. With these drugs the doctor, and not the patient, must be warned by the manufacturer.

Id. at 580-81 (citation and footnote omitted).

Other Michigan decisions apply the learned intermediary rule to pharmacists.  Adkins v. Mong, 425 N.W.2d 151, 152 (Mich. App. 1988) (“defendant pharmacy in this case had no duty to warn plaintiff of the potential side effects of the substances it was dispensing to plaintiff in accordance with the prescriptions submitted, all of which were valid on their face”); Stebbins v. Concord Wrigley Drugs, Inc., 416 N.W.2d 381, 386-88 (Mich. App. 1987) (“a pharmacist has no duty to warn the patient of possible side effects of a prescribed medication where the prescription is proper on its face and neither the physician nor the manufacturer has required that any warning be given to the patient by the pharmacist”).

Since Michigan appellate precedent concerning the rule is rather old, here are some more recent trial court decisions (from the current century) demonstrating that it continues to be applied in Michigan prescription medical product liability litigation.  Groulx v. Janssen Pharmaceuticals, 2025 WL 415725, at *4 (E.D. Mich. Feb. 6, 2025) (“Plaintiffs’ claim is further foreclosed under the learned intermediary doctrine.  “Michigan has adopted and follows the learned intermediary doctrine, which holds that a manufacturer has no duty to warn the ultimate consumer if the product is provided for use by a sophisticated consumer.”) (quoting Hill) (drug); Hill v. Bayer Corp., 485 F. Supp.3d 843, 854 (E.D. Mich. 2020) (“Michigan has adopted and follows the learned intermediary doctrine, which holds that a manufacturer has no duty to warn the ultimate consumer if the product is provided for use by a sophisticated consumer.  This doctrine has been expressly applied in the medical device context, with the result that adequate warnings are owed to physicians and surgeons and not to their patients.”) (citation omitted); McClarty v. C.R. Bard Inc., 2020 WL 6075520, at *10 (E.D. Mich. Oct. 15, 2020) (“Under the learned intermediary doctrine, a manufacturer is exempt from its duty to warn ultimate users of prescription drugs and medical devices of inherent dangers because patients rely on the expertise of a doctor when utilizing a medical device or prescribed drug and may not appreciate warnings provided by the manufacturer.”) (device); Avendt v. Covidien Inc., 262 F. Supp.3d 493, 521 (E.D. Mich. 2017) (“Michigan has adopted and follows the learned intermediary doctrine, which holds that a manufacturer has no duty to warn the ultimate consumer if the product is provided for use by a sophisticated consumer.”) (device); Tice v. Zimmer Holdings, Inc., 2015 WL 4392985, at *5 (W.D. Mich. July 15, 2015) (“the Court is satisfied that the Devices are prescription devices to which the learned intermediary doctrine applies”); Gillett v. Sofamor, S.N.C., 2001 WL 1135304, at *7 (E.D. Mich. Sept. 13, 2001) (“Michigan has recognized the ‘learned intermediary doctrine’ with regard to medical devices.”).

Minnesota

More than fifty years ago, the Minnesota Supreme Court stated that “[t]he manufacturer has no duty to warn the lay public regarding prescription drugs.”  Mulder v. Parke Davis & Co., 181 N.W.2d 882, 885 n.1 (Minn. 1970).  That court reiterated this holding in Gray v. Badger Mining Corp., 676 N.W.2d 268, 275 (Minn. 2004), stating that in Mulder “we recognized that the learned intermediary defense was available in a claim for failure to warn of the dangers of a drug.”  Id. at 275-76.  Gray was not a prescription medical product case.

Lots of federal courts apply the rule to medical devices under Minnesota law.  Kapps v. Biosense Webster, Inc., 813 F. Supp.2d 1128, 1152 (D. Minn. 2011), held:

Under the learned-intermediary doctrine, a maker of drugs or medical devices has a duty to warn only doctors (the learned intermediaries) − and not patients − about the dangers associated with a drug or medical device. Thus, the learned-intermediary doctrine forecloses a patient’s failure-to-warn claim if a drug company or medical-device manufacturer provides an adequate warning to the patient’s doctor.

Id. at 1152 (citations omitted).  Most of the rest, however, are not reported.  See In re Bard Implanted Port Catheter Products Liability Litigation, 2026 WL 622645, at *9 (D. Ariz. March 5, 2026) (applying Minnesota law); Juliar v. Ethicon, Inc., 2022 WL 23624, at *2 (D. Minn. Jan. 3, 2022); Dolan v. Boston Scientific Corp., 2021 WL 698777, at *3 (D. Minn. Feb. 23, 2021); Marshall v. Smith & Nephew, Inc., 2020 WL 362803, at *7 (D. Minn. Jan. 22, 2020); Perry v. Boston Scientific Family, 2016 WL 10637082, at *5 (Mag. D. Minn. Dec. 1, 2016), adopted, 2017 WL 44845 (D. Minn. Jan. 4, 2017); Thompson v. Zimmer Inc., 2013 WL 5406628, at *3 (D. Minn. Sept. 25, 2013); Wehner v. Linvatech Corp., 2008 WL 495525, at *4 (D. Minn. Feb. 20, 2008); Johnson v. Zimmer, Inc., 2004 WL 742038, at *9 (D. Minn. March 31, 2004); In re Orthopedic Bone Screw Litigation, 1999 WL 628688, at *14 (D. Minn. March 8, 1999), aff’d mem., 221 F.3d 1343 (8th Cir. 2000); Bruzer v. Danek Medical, Inc., 1999 WL 613329, at *6 (D. Minn. March 8, 1999); Greiner v. Sofamor, S.N.C., 1999 WL 716891, at *5 (D. Minn. March 8, 1999); Mozes v. Medtronic, Inc., 14 F. Supp.2d 1124, 1130 (D. Minn. 1998); Kociemba v. G.D. Searle & Co., 680 F. Supp. 1293, 1305-06 (D. Minn. 1988).  See also In re Bard Implanted Port Catheter Products Liability Litigation, 2026 WL 622645, at *9 (D. Ariz. March 5, 2026) (applying Minnesota law).

We haven’t found any Minnesota biologic or pharmacy cases involving the rule.

Mississippi

In Mississippi, the learned intermediary rule is now required by statute as to both drugs and medical devices.  Miss. Code §11-1-63(c)(ii) (requiring warnings “in the case of a prescription drug, medical device or other product that is intended to be used only under the supervision of a physician or other licensed professional person,” be given to “a physician or other licensed professional who prescribes the drug, device or other product”).

The statute was not a big change from Mississippi common law.  The Mississippi Supreme Court has consistently followed the rule.

The general rule is that where prescription drugs are concerned, a manufacturer’s duty to warn only extends to physicians and not to laymen.  If the language of the warning is adequate then the drug manufacturer ordinarily is freed from liability.  The “learned intermediary” doctrine is the basis for this rule.

Janssen Pharmaceutica, Inc. v. Bailey, 878 So.2d 31, 57 (Miss. 2004) (citation and quotation marks omitted).  Janssen quoted Wyeth Laboratories, Inc. v. Fortenberry, 530 So.2d 688, 691 (Miss. 1988), the first Mississippi high court decision to adopt the learned intermediary rule – which did so in a vaccine/biologic context.  Accord Bennett v. Madakasira, 821 So.2d 794, 804 (Miss. 2002) (“Under Mississippi law, as in virtually every jurisdiction in a prescription drug case, a manufacturer of a prescription drug has no duty to warn the patient, consumer, or general public of adverse effects.”) (drug).

In Moore v. Memorial Hospital, 825 So.2d 658 (Miss. 2002), the court extended the learned intermediary rule to pharmacists.

We . . . extend the learned intermediary doctrine to pharmacists.  As one court has stated, “the cornerstone of the learned intermediary doctrine is the ability of the physician to intervene between the drug and the patient, and to make an informed decision as to the course of treatment based on the physician’s knowledge of the drug as well as the propensities of the patient.”  The physician is best situated to know the propensities of a drug and to know the needs and characteristics of his patient.

Id. at 664 (citation omitted).  Moore also noted that the learned intermediary rule “has been extended to insulate from liability the manufacturers of medical devices available through physicians.”  Id. at 662 n.6 (citing Cather v. Catheter Technology Corp., 753 F. Supp. 634 (S.D. Miss. 1991)).

Missouri

Over 50 years ago, the Missouri Supreme Court held, in Krug v. Sterling Drug, Inc., 416 S.W.2d 143 (Mo. 1967), that the “basic rule and duty” in products liability litigation was:

Where the drug is a prescription drug, the manufacturer has a duty to properly warn the doctor of the dangers involved.  It is incumbent upon the manufacturer to bring the warning home to the doctor.

Id. at 146-47 (citations and quotation marks omitted).  That court has not decided another learned intermediary case since.  Accord Johnson v. Upjohn Co., 442 S.W.2d 93, 95 (Mo. App. 1969) (“In the case of prescription drugs . . . warning to the medical profession in such manner is all that is required and constitutes warning to the patient as well.”) (citing Krug); Brinkley v. Pfizer, Inc., 772 F.3d 1133, 1137 (8th Cir. 2014) (“Missouri too adheres to the learned intermediary doctrine.”) (citation and quotation marks omitted).

A Missouri intermediate appellate court applied the learned intermediary rule to a biologic in Doe v. Alpha Therapeutic Corp., 3 S.W.3d 404 (Mo. App. 1999), pointing out that “Missouri courts adhere to the learned intermediary doctrine” and that “the manufacturer has a duty to properly warn the doctor of the dangers involved.”  Id. at 419.

The learned intermediary doctrine is a corollary to the rule that a manufacturer of prescription drugs or products discharges its duty to warn by providing the physician with information about risks associated with those products.  The physician acts as a “learned intermediary” between the manufacturer and the patient and any warning given to the physician is deemed a warning to the patient.

Id. (citations omitted).

The Eighth Circuit applied the rule to medical devices.  Kirsch v. Picker International, Inc., 753 F.2d 670 (8th Cir. 1985).

Missouri courts have held that in cases involving prescription drugs, the manufacturer has a duty to properly warn the doctor of the danger involved.  The physician acts as a “learned intermediary” between the manufacturer and the patient.  Thus, a warning to the doctor is deemed a warning to the patient; the manufacturer need not communicate directly with all ultimate users of prescription drugs.

Id. at 671.

Since Missouri appellate precedent concerning the rule is somewhat old, here are some more recent trial court cases demonstrating that it continues to be applied in Missouri prescription medical product liability litigation.  Seals v. Wright Medical Technologies, Inc., 2022 WL 6096818, at *14 (E.D. Mo. Oct. 7, 2022) (“Missouri courts apply the learned-intermediary doctrine in medical-equipment or medical-device cases involving failure-to-warn claims.) (citations omitted); Davis v. Eisai, Inc., 2021 WL 4810704, at *2 (W.D. Mo. Oct. 14, 2021) (“to the degree Plaintiff’s failure to warn claims are premised on [plaintiff’s] failure to warn anyone other than Plaintiff’s doctor, they fail to state a claim and are dismissed”); Rash v. Boston Scientific Corp., 2020 WL 8455124, at *4 (W.D. Mo. Nov. 12, 2020) (“because of the application of the learned intermediary doctrine, [plaintiff’s] claim for negligent failure to warn is viable only to the extent [she] alleges [defendant] failed to warn her treating physician of the risks associated with Product”); Bayes v. Biomet, Inc., 2020 WL 5095346, at *12 (E.D. Mo. Aug. 28, 2020) (“Missouri courts apply the learned intermediary doctrine in prescription drug and medical equipment or device cases involving failure to warn claims.”); Abt v. Ethicon, Inc., 2020 WL 4887022, at *2 (E.D. Mo. Aug. 20, 2020) (same); Guilford v. Boston Scientific Corp., 2020 WL 1668279, at *2 (W.D. Mo. April 3, 2020) (“Because Defendant owed no duty to Plaintiff or the medical community at large, Plaintiff’s claims for failure to warn must be dismissed to the extent they are premised on Defendant’s failure to warn anyone other than Plaintiff’s physician.”); Redd v. DePuy Orthopaedics, Inc., 48 F. Supp.3d 1261, 1270 (E.D. Mo. 2014) (“The learned intermediary doctrine provides that a drug manufacturer has a duty to warn a physician of the risks involved with its product. The physician then acts as a ‘learned intermediary’ between the manufacturer and the physician’s patient so that any warning given to the physician is deemed a warning to the patient.”).

We did not find any Missouri precedent applying the learned intermediary rule to a pharmacist.

Montana

In Hill v. Squibb & Sons, 592 P.2d 1383, 1387-88 (Mont. 1979), the court recognized that “As a general rule, the duty of a drug manufacturer to warn of the dangers inherent in a prescription drug is satisfied if adequate warning is given to the physician who prescribes it.”) (citations omitted).  In Stevens v. Novartis Pharmaceuticals Corp., 247 P.3d 244 (Mont. 2010), the court cautioned that while “[t]he learned intermediary doctrine has been widely accepted, in some form, for the better part of the past century,” id. at 492, its contours in terms of “expansion of the possible class of learned intermediaries” were less certain” and that “a variety of different healthcare providers may be considered learned intermediaries.”  Id. at 493.  Thus, Stevens ultimately “concur[red] with authorities who consider the learned intermediary to be the healthcare professional actually responsible for making decisions related to the patient’s care.”  Id. at 495.

The learned intermediary rule in Montana has been applied to medical devices.  Dalbotten v. C.R. Bard, Inc., 2023 WL 157735, at *3 (D. Mont. Jan. 11, 2023) (“Under the learned intermediary doctrine, a medical or pharmaceutical manufacturer’s duty to warn runs to the prescribing and treating physicians, rather than necessarily to the patients themselves.”).

We don’t know of any Montana cases involving the rule’s application in cases involving biologics or pharmacists.

Nebraska

The Nebraska Supreme Court adopted the learned intermediary rule in Freeman v. Hoffman-La Roche, Inc., 618 N.W.2d 827 (Neb. 2000). 

Pharmaceutical products have historically been treated differently in regard to a duty to warn. . . .  [I]n cases involving prescription drugs, it is widely held that the duty to warn extends only to members of the medical profession and not to the consumer.  This concept [is] known as the learned intermediary doctrine. . . .  The learned intermediary doctrine is provided for in §6(d) of the Third Restatement. . . .

We have not specifically adopted the learned intermediary doctrine as the applicable test for determining whether a manufacturer may be liable for a warning defect in prescription drug cases.  However, with a few exceptions . . ., the doctrine is followed in virtually all jurisdictions that have considered whether to adopt it.  The doctrine as stated in the Third Restatement has also been adopted in other jurisdictions.  We adopt §6(d) of the Third Restatement.  Accordingly, we apply the learned intermediary doctrine to [this] case.

Id. at 841-42 (citations and block quotations omitted).

The learned intermediary rule has also been applied, under Nebraska law to medical devices.

Although Freeman involved a “prescription drug,” the Restatement treats “medical device[s]” no differently, which suggests that the Nebraska Supreme Court would, if faced with the question, apply the learned-intermediary doctrine to devices.

Ideus v. Teva Pharmaceuticals USA, Inc., 986 F.3d 1098, 1101 (8th Cir. 2021).

The relevant consumer for design defect claims is the patient, not the physician. “Although not stated explicitly in Nebraska case law, it is implicit that the consumer or user of a medical device or prescription drug is the patient − not the physician.”).

Thelen v. Somatics, LLC, 156 F.4th 1115, 1125 (11th Cir. 2025) (applying Nebraska law) (quoting Langner v. Boston Scientific Corp., 492 F. Supp. 3d 925, 933 (D. Neb. 2020)).

A trial court in another state applied the Nebraska learned intermediary rule to a biologic.  Cleary v. Biogen Idec, Inc., 2017 WL 8226624, at *11 (Mass. Super. Sept. 8, 2017).

We haven’t found any Nebraska cases involving the rule’s application to a defendant pharmacist.

Nevada

Nevada has adopted the learned intermediary rule.  In Klasch v. Walgreen Co., 264 P.3d 1155 (Nev. 2011), involving a pharmacy defendant, the Nevada Supreme Court held:

Traditionally, the learned-intermediary doctrine has been used to insulate drug manufacturers from liability in products-liability lawsuits.  Under the learned-intermediary doctrine, a drug manufacturer is immune from liability to a patient taking the manufacturer’s drug so long as the manufacturer has provided the patient’s doctor with all relevant safety information for that drug.  It is then up to the patient’s doctor − who has the benefit of knowing the patient’s specific situation − to convey to the patient any information that the doctor deems relevant.

Jurisdictions adopting the learned-intermediary doctrine in the context of pharmacist/customer tort litigation have put forth a similar rationale:  that between the doctor and the pharmacist, the doctor is in the best position to warn the customer of a given medication’s generalized risks. . . .  In this sense, the learned-intermediary doctrine preserves the pharmacist’s role as a conduit for dispensing much-needed prescription medications.

Because we believe that these public-policy considerations are sound, we adopt the learned-intermediary doctrine in the context of pharmacist/customer tort litigation.

Id. at 1158-59 (footnotes omitted).  See Sanchez v. Wal-Mart Stores, Inc., 221 P.3d 1276, 1280-84 (Nev. 2009) (also rejecting pharmacist warning liability without mentioning the rule).

Previously, a majority of the Nevada Supreme had applied the learned intermediary rule in a biologic/vaccine case in Allison v. Merck & Co., 878 P.2d 948 (Nev. 1994), but not all in the same opinion.  A two-justice plurality acknowledged the learned intermediary rule, but applied the “mass immunization” exception:

[W]e do not believe that [the prescriber’s] advice . . . that “it was time” for [plaintiff] to receive his MMR II vaccine is the type of individualized medical judgment contemplated by the learned intermediary defense. . . .  Accordingly, the mass immunization exception does apply to this case.

Id. at 958 n.16.  As the plurality indicated, the two-justice Allison dissent considered “summary judgment [to be] appropriate in this case [given] the applicability of the . . . ‘learned intermediary defense.’” Id.  That made a majority of the court.  Here’s what the dissent in Allison said:

[T]he learned intermediary defense . . . is one that this court has never addressed.  A learned intermediary [is] as a medical expert, such as a prescribing physician, whose task is to weigh the benefits of any medication against possible dangers and to make an individualized medical judgment bottomed on a knowledge of both patient and palliative.  The pharmaceutical company’s duty, in selling prescription drugs, is to warn only the prescribing physician, who acts as a ‘learned intermediary’ between manufacturer and consumer.

Id. at 969 (citations and quotation marks omitted).  Unlike the plurality, the dissent found that “the prescribing physician[] was a learned intermediary in this case,” and thus no exception to the rule applied.  Id. at 969 (a manufacturer “should not be held liable simply because the learned intermediary failed to perform his duty to warn his patient”).  No justice in Allison rejected the learned intermediary rule itself.

No Nevada appellate decisions have applied the learned intermediary rule in the medical device context.  However, a raft of federal district court decisions have done so. Whipple v. C.R. Bard, Inc., 2024 WL 1345227, at *5-6 (D. Nev. March 30, 2024); Carter v. Johnson & Johnson, 2022 WL 4625960, at *3 (D. Nev. Sept. 30, 2022); Hix v. Zimmer Biomet Holdings, Inc., 2022 WL 946914, at *5-6 (D. Nev. March 29, 2022); Carter v. Ethicon, Inc., 2021 WL 1226531, at *2, 4 (D. Nev. March 31, 2021); Young v. Ethicon, Inc., 2021 WL 6101637, at *4 (D. Nev. Jan. 29, 2021); Heinrich v. Ethicon, Inc., 455 F. Supp.3d 968, 973-74 (D. Nev. 2020); Miller v. Depuy Synthes Sales, Inc., 2019 WL 4016207, at *6 (D. Nev. Aug. 26, 2019); Phillips v. C.R. Bard, Inc., 2014 WL 7177256, at *9 (D. Nev. Dec. 16, 2014); Moses v. Danek Medical, Inc., 1998 WL 1041279, at *4-5 (D. Nev. Dec. 11, 1998); Kioudjian v. Technogym USA Corp., 2018 WL 3702005, at *1 (Nev. Dist. June 26, 2018).

As discussed, the Nevada Supreme Court has applied the learned intermediary rule to prescription drugs, but only in the pharmacy context.  Several Nevada law decisions by recognize that the same considerations apply to prescription drugs generally, including the Ninth Circuit in Kwasniewski v. Sanofi-Aventis U.S., LLC, 637 F. Appx. 405, 406 (9th Cir. 2016) (“holding that under Nevada law, there is no duty to warn on the part of a non-prescribing therapist”).  Nevada trial courts also apply the rule to prescription drugs.  Kwasniewski v. Sanofi-Aventis U.S. LLC, 2018 WL 1567851, at *4 (D. Nev. March 30, 2018); Flowers v. Eli Lilly & Co., 2015 WL 12622058, at *2-3 (D. Nev. July 10, 2015); Harrelson v. Boehringeringelheim Pharmaceuticals, Inc., 2024 WL 3585784, at *10 (Nev. Dist. May 15, 2024); Adams v. Teva Parenteral Medicines, Inc., 2024 WL 1944157, at *3-5 (Nev. Dist. Feb. 4, 2024).

Stephens v. Zoetis, Inc., 2026 WL 837353, at *1-2 (D. Nev. March 25, 2026), applied the learned intermediary rule applies to veterinary drugs under Nevada law.

New Hampshire

The only New Hampshire state court decision to address the learned intermediary rule is a trial court decision following it in the drug context:

The learned intermediary doctrine creates an exception to the general rule that one who markets goods must warn foreseeable ultimate users about the inherent risks of his products and, in the prescription drug context provides that a drug manufacturers duty is limited to the obligation to advise the prescribing physician of any potential dangers that may result from the use of the drug.

State v. Purdue Pharma Inc., 2018 WL 4566129, at *6 (N.H. Super. Sept. 18, 2018).

Federal courts have also held that New Hampshire would follow the rule.  The First Circuit has applied the learned intermediary rule twice in New Hampshire prescription drug cases.  Brochu v. Ortho Pharmaceutical Corp., 642 F.2d 652, 656 (1st Cir. 1981) (“In cases involving ethical drugs, the manufacturer must warn the physician, not the patient.”) (citations omitted); McCue v. Norwich Pharmacal Co., 453 F.2d 1033, 1035 (1st Cir. 1972) (“the New Hampshire court would follow others in imposing upon a drug manufacturer an affirmative duty to warn the medical profession of the dangerous side effects that might result”).

Federal district courts interpreting New Hampshire law likewise apply the learned intermediary rule to medical device cases. 

[T]he learned intermediary doctrine holds that a manufacturer’s duty to warn regarding the risks associated with a product runs to a patient’s treating physician (or other learned intermediary) rather than directly to the patient.  The parties and the court agree that, as a matter of New Hampshire law, the learned intermediary doctrine applies to duties owed by pharmaceutical manufacturers. . . .  [W]hile plaintiff argues that there is an unresolved question as to whether the doctrine applies to medical device manufacturers, plaintiff offers no rationale for distinguishing between the pharmaceutical and the medical device contexts for purposes of the doctrine.  Courts that have considered the matter have uniformly found that the doctrine is applicable with equal force in both contexts.

Luna v. Atrium Medical Corp., 561 F. Supp.3d 62, 69-70 (D.N.H. 2021) (citations omitted).  Accord O’Neil v. Somatics, LLC, 2022 WL 4611938, at *8 (D.N.H. Sept. 30, 2022) (“I have no doubt that the court will follow the many courts in other jurisdictions that have applied the [learned intermediary] doctrine in medical device cases.”); cf. Nelson v. Dalkon Shield Claimants Trust, 1994 WL 255392, at *4 (D.N.H. June 8, 1994) (“it is generally accepted that in a case involving medical products prescribed or used by a physician or trained medical personnel, the warning runs to the physician not the patient.”) (citation and quotation marks omitted) (pre-1976 IUD)

We found no pharmacist or biologic cases from New Hampshire.

New Jersey

As to prescription drugs, the learned intermediary rule is required by statute in New Jersey.  N.J. Stat. §2A:58C-4.

An adequate product warning or instruction is one that a reasonably prudent person in the same or similar circumstances would have provided with respect to the danger and that communicates adequate information on the dangers and safe use of the product, taking into account the characteristics of, and the ordinary knowledge common to, the persons by whom the product is intended to be used, or in the case of prescription drugs, taking into account the characteristics of, and the ordinary knowledge common to, the prescribing physician.

(Emphasis added).  See In re Accutane Litigation, 194 A.3d 503, 508 (N.J. 2018) (“New Jersey has adopted the ‘learned intermediary’ doctrine, which recognizes that a prescribing doctor has the primary responsibility of advising the patient of the risks and benefits of taking a particular medication.”) (citations omitted).

Likewise, the New Jersey Supreme Court has recognized that the rule applies to all prescription medical products.  Perez v. Wyeth Laboratories, Inc., 734 A.2d 1245, 1257 (N.J. 1999), applied the rule to a product that “exhibit[ed] characteristics both of a medical device implanted in the body and of a drug.”  Id. at 1257.

With respect to drugs and medical devices, our state law has adopted the “learned intermediary” doctrine, under which a pharmaceutical manufacturer generally discharges its duty to warn the ultimate user of prescription drugs by supplying physicians with information about the drug’s dangerous propensities.  This doctrine recognizes that a prescribing doctor has the primary responsibility of advising the patient of the risks and benefits of taking a particular medication.  Thus, it is the physician’s responsibility to pass on to the parties the information that enables the patient to use the product safely. . . .  Where a failure-to-warn case involves something advised by a physician, such as a prescription drug or a medical device, the issue is whether the warning should have been given to the prescribing physician.

Hrymoc v. Ethicon, Inc., 249 A.3d 191, 217 (N.J. Super. App. Div. 2021) (citations and quotation marks omitted), aff’d on other grounds, 297 A.3d 1245 (N.J. 2023).

Niemiera v. Schneider, 555 A.2d 1112, 1117 (N.J. 1989), applied the learned intermediary rule in a vaccine case:

In New Jersey, as elsewhere, we accept the proposition that a pharmaceutical manufacturer generally discharges its duty to warn the ultimate user of prescription drugs by supplying physicians with information about the drug’s dangerous propensities.  This concept is known as the “learned intermediary” rule because the physician acts as the intermediary between the manufacturer and the consumer. . . .  We are satisfied that sufficient reasons exist with respect to the . . . vaccine to conclude that the “learned intermediary” doctrine should apply.

Id. at 1117 (citation and footnote omitted).

Shamy v. Gamao, 2023 WL 6939135 (N.J. Super. App. Div. Oct. 20, 2023), recognized that the rule also applies in product liability cases brought against pharmacies.

[T]he [learned intermediary] doctrine applies to pharmacies that accurately fill prescriptions written by physicians in amounts and at frequencies within reasonable medical standards. . . .  Because the decision to prescribe a specific drug involves an analysis of the patient’s unique condition and a balancing of the risks and benefits of a given drug, the cases extending the learned intermediary doctrine to pharmacists reason that imposing a duty to warn on the pharmacist would intrude on the doctor-patient relationship and would force the pharmacist to practice medicine without a license.

Id. at *5 (citations and quotation marks omitted).

New Mexico

While the New Mexico Supreme Court has never addressed the learned intermediary rule, New Mexico intermediate appellate courts have applied it repeatedly.  As to prescription drugs, Richards v. Upjohn Co., 625 P.2d 1192, 1195 (N.M. App. 1980), declared:

A drug manufacturer has a duty to warn the medical profession of the dangers of its drugs which it knew or should have known to exist.  The manufacturer is liable to a patient who suffers injuries from a drug as a result of the manufacturer’s breach of its duty to warn the doctor of the dangers of the drug.

Id. at 1195-96 (citations omitted).  Accord Silva v. SmithKlineBeecham Corp., 2013 WL 4516160, at *2-3 (N.M. App. Feb. 7, 2013) (quoting and following Hines); Serna v. Roche Laboratories, Division of Hoffman-LaRoche, Inc., 684 P.2d 1187, 1189 (N.M. App. 1984) (“Where the product is a prescription drug, the manufacturer’s duty to warn is fulfilled if it warns the physician, not the patient.”) (citation omitted).  Hines v. St. Joseph’s Hospital, 527 P.2d 1075, 1077 (N.M. App. 1974), treated a biologic (blood) as a prescription drug, holding that “The [evidence] establish[es] that blood is a prescription drug.  Ordinarily the manufacturer’s duty to warn of the dangers of prescription drugs is to the attending physician, not the patient.”  Id. at 1077 (citations omitted).

In a medical device case, Perfetti v. McGahn Medical, 662 P.2d 646 (N.M. App. 1983), held:

The parties dispute as to whom the warning was due − plaintiff or her surgeon.  The evidence is uncontradicted that federal law restricted this prosthesis “to sale by or on the order of a licensed physician”; that plaintiff had no contact with defendant and received no warning from defendant.  A manufacturer of a product which is obtainable only through the services of a physician, fulfills its duty if it warns the physician of the dangers attendant upon its use, and need not warn the patient as well.

Id. at 650 (citations and quotation marks omitted).  Accord Jones v. Minnesota Mining & Manufacturing Co., 669 P.2d 744, 748 (N.M. App. 1983) (“under the circumstances of these cases, any warnings to be given would be to the radiotherapists”).

We don’t know of any New Mexico pharmacist cases.

Finally, we point out that Nowell v. Medtronic Inc., 372 F. Supp.3d 1166 (D.N.M. 2019), aff’d, 2021 WL 4979300 (10th Cir. Oct. 27, 2021), applied the learned intermediary rule in a medical device case:

Pursuant to the learned-intermediary doctrine, the prescribing physician acts as a learned intermediary between a prescription drug manufacturer and the ultimate user, and the manufacturer satisfies its duty to warn by providing adequate warnings to the prescribing physician.  The learned intermediary doctrine states that once a manufacturer warns a doctor about a drug’s inherent dangers, it has fulfilled its legal duty to provide a warning. . . .  “The overwhelming majority of jurisdictions to address this issue apply the learned intermediary doctrine to define a pharmaceutical company’s duty to warn of risks associated with the use of a prescription drug.

Id. at 1128-29 (citations and quotation marks omitted).  We mention this because Nowell was decided by the same New Mexico judge who had, several years earlier, questioned whether New Mexico followed the rule at all.  See Rimbert v. Eli Lilly & Co., 577 F. Supp. 2d 1174, 1214-16 (D.N.M. 2008).  Should any plaintiff challenge the learned intermediary rule in New Mexico citing Rimbert, the proper response is that Nowell demonstrates that the same judge has since recanted that outré position and accepts the learned intermediary rule as New Mexico law.

New York

The New York Court of Appeals adopted the learned intermediary (a/k/a “informed intermediary” in NY) rule in Spensieri v. Lasky, 723 N.E.2d 544, 549 (N.Y. 1999), and Martin v. Hacker, 628 N.E.2d 1308, 1311 (N.Y. 1993).  Martin, in a prescription drug case, held:

Warnings for prescription drugs are intended for the physician, whose duty it is to balance the risks against the benefits of various drugs and treatments and to prescribe them and supervise their effects.  The physician acts as an “informed intermediary” between the manufacturer and the patient; and, thus, the manufacturer’s duty to caution against a drug’s side effects is fulfilled by giving adequate warning through the prescribing physician, not directly to the patient.

Id. at 601 (citations omitted).  Similarly, Spensieri recognized:

The learned intermediary doctrine focuses on the scope of a drug manufacturer’s duty to warn of the dangers of using the drug in question.  That duty is fulfilled by giving adequate warning to the prescribing physician.  The physician must then balance the risks and benefits of various drugs and treatments and act as an “informed intermediary” between manufacturer and patient.

Id. at 549 (Martin citations omitted).

While New York’s highest court has not applied the learned intermediary rule in a medical device case, numerous other New-York-law appellate decisions have done so.  Bravman v. Baxter Healthcare Corp., 984 F.2d 71, 75 (2d Cir. 1993) (“In cases such as this one, the duty to warn is owed to the medical community and, more specifically, to the treating physician who is to act as an ‘informed intermediary’ between the manufacturer and patient.”) (citation omitted); Fane v. Zimmer, Inc., 927 F.2d 124, 129 (2d Cir. 1991) (The “device is not available to the public, but rather is available only by prescription and thus . . . information is disseminated to physicians and the medical community rather than to the patient directly.  Warnings are furnished to the medical community as the ‘informed intermediary’ between the manufacturer and the patient.”); Tomaselli v. New York & Presbyterian Hospital, 728 F. Appx. 41, 43 (2d Cir. 2018) (“plaintiffs’ strict liability claims against the defendants fail under the informed intermediary doctrine”); Donovan v. Centerpulse Spine Tech Inc., 416 F. Appx. 104, 107 (2d Cir. 2011) (“Under New York law, the physician acts as an ‘informed intermediary’ between the manufacturer and the patient; and, thus, the manufacturer’s duty to caution against a device’s side effects is fulfilled by giving adequate warning through the treating] physician”); Silverstein v. CoolSculpting – Zeltiq Aesthetics, Inc., 229 N.Y.S.3d 44, 46 (App. Div. 2025) (“Because the [device] is a FDA Class II medical device that requires a prescription, [defendant’s] duty to warn runs to physicians, not directly to patients.”); Mulhall v. Hannafin, 841 N.Y.S.2d 282, 285 (App. Div. 2007) (“The manufacturer’s duty, under New York law, is to warn the medical community, not the patient of the product’s risk.”) (citation omitted); Cutroneo v. Dryer, 784 N.Y.S.2d 247, 249 (App. Div. 2004) (“Where the risks of a medical device are thoroughly disclosed to the treating physician, the manufacturer is insulated from liability for a failure to warn the patient of same.”) (citation omitted); Banker v. Hoehn, 718 N.Y.S.2d 438, 440 (App. Div. 2000) (“Under the doctrine of ‘learned intermediary,’ the manufacturer of the medical device satisfies its duty to warn of potential adverse effects when it adequately warns medical professionals who use the device in the treatment of patients”); Bukowski v. CooperVision Inc., 592 N.Y.S.2d 807, 809 (App. Div. 1993) (“The informed intermediary doctrine has been extended to apply to certain medical devices”) (citations omitted).

The learned intermediary rule also protects New York pharmacists unless “the prescription was so clearly contraindicated that ordinary prudence required the pharmacist to take additional measures.”  Abrams v. Bute, 27 N.Y.S.3d 58, 71 (App. Div. 2016).

Since “the physician acts as an ‘informed intermediary’” . . . “it is the prescribing physician who is responsible for exercising the professional judgment needed to determine whether a particular course of treatment is appropriate for a given patient.  Courts have been reluctant to impose a standard of care on pharmacists that would go beyond the need to accurately fill a prescription and require pharmacists to exercise their own professional judgment in a manner that could conflict with that of the prescribing physician.

Id. at 65-66 (citations omitted).  Accord In re New York County Diet Drug Litigation, 691 N.Y.S.2d 501, 502 (App. Div. 1999); Bichler v. Willing, 397 N.Y.S.2d 57, 559 (App. Div. 1977). 

The New York learned intermediary rule also applies to biologics.  Wholey v Amgen, Inc., 2017 WL 931326, at *9 (N.Y. Sup. March 8, 2017), aff’d, 86 N.Y.S.3d 16 (App. Div. 2018).

North Carolina

In North Carolina, the learned intermediary rule applies, by statute, to prescription drugs.

Notwithstanding subsection (a) of this section, no manufacturer or seller of a prescription drug shall be liable in a products liability action for failing to provide a warning or instruction directly to a consumer if an adequate warning or instruction has been provided to the physician or other legally authorized person who prescribes or dispenses that prescription drug for the claimant unless the United States Food and Drug Administration requires such direct consumer warning or instruction to accompany the product.

N.C. Gen. Stat. §99B-5(c).

Under North Carolina law, courts have repeatedly applied the learned intermediary rule to prescription medical devices.  Asby v. Medtronic, Inc., 673 F. Supp.3d 787, 794 (E.D.N.C. 2023) (“Although North Carolina law explicitly applies the learned intermediary doctrine to prescription drugs, the doctrine also applies to medical devices.”); Teague v. Johnson & Johnson, 578 F. Supp.3d 743, 750 (E.D.N.C. 2022) (“the learned intermediary doctrine would apply just as equally to the manufacturer of a medical device”); Smith v. Ethicon, Inc., 2020 WL 3256926, at *2 (M.D.N.C. June 16, 2020) (“Although the North Carolina Supreme Court has not spoken on whether the limitation on pharmaceutical liability outlined in §99B-5(c) likewise extends to medical devices . . ., several federal courts . . . have presumed that it does.”); Carlson v. Boston Scientific Corp., 2015 WL 5732107 (W.D.N.C. Sept. 30, 2015) (“the North Carolina Supreme Court would apply the learned intermediary doctrine in a case involving a medical device such as this”), aff’d, 856 F.3d 320 (4th Cir. 2017); Block v. Woo Young Medical Co., 937 F. Supp.2d 1028, 1035 n.5 (D. Minn. 2013) (“North Carolina adheres to the learned intermediary doctrine”) (applying North Carolina law); Baraukas v. Danek Medical, Inc., 2000 WL 223508, at *4 (M.D.N.C. Jan. 13, 2000) (“where a defendant manufactures a product which is dispensed to patients by doctors, rather than directly, the defendant has a duty to warn only the doctor, rather than the patients North . . . Carolina courts would adhere to the learned intermediary doctrine.”); Padgett v. Synthes, Ltd. (U.S.A.), 677 F. Supp. 1329, 1335 (W.D.N.C. 1988) (“warnings when given in the insert to the physician were sufficient notice to Plaintiff”), aff’d, 872 F.2d 418 (4th Cir. 1989).

Under North Carolina law, the learned intermediary rule has also been applied to biologics.  In re Gardasil Products Liability Litigation, 724 F. Supp.3d 474, 489 n.17 (W.D.N.C. 2024) (“North Carolina . . . recognize[s] the learned intermediary doctrine”), aff’d, 151 F.4th 178 (4th Cir. 2025); Cowley v. Abbott Laboratories, Inc., 476 F. Supp.2d 1053, 1060 (W.D. Wis. 2007) (treating a biologic as a “drug” under §99B-5(c)) (applying North Carolina law); Foyle v. Lederle Laboratories, 674 F. Supp. 530, 536 (E.D.N.C. 1987) (“The doctor is responsible for gathering the information, weighing the dangers and benefits, and making a decision in the best interest of the patient.  This analysis supports the “learned intermediary” doctrine.”).

A North Carolina appellate court rejected pharmacist liability on learned intermediary grounds in Batiste v. American Home Products Corp., 231 S.E.2d 269, 274-76 (N.C. App. 1977).

Here the drug purchased by plaintiff was not available to the general public in the sense that it was available for purchase by any customer who came in the drug store. . . .  It was available only to those who had previously seen their physician and obtained from the physician a prescription directing the druggist to supply the drug.  Obviously the plaintiff patient did not rely on the druggist. . . .  This reliance had been properly placed with her physician.

Id. at 276.

North Dakota

The North Dakota Supreme Court has never adjudicated a learned intermediary case.  In the federal courts, Ehlis v. Shire Richwood, Inc., 367 F.3d 1013, 1017 (8th Cir. 2004), predicted that North Dakota, like its sister states, would follow the rule.

[T]he district court noted an overwhelming majority of jurisdictions have adopted the learned intermediary doctrine. . . .  Because the precedent is truly overwhelming and the policy enunciated by the learned intermediary doctrine is sound, we conclude the district court correctly ruled the North Dakota Supreme Court would adopt the learned intermediary doctrine.

Id. at 1017 (citation omitted).  Accord Harris v. McNeil Pharmaceutical, 2000 WL 33339657, at *4 n.4 (D.N.D. Sept. 5, 2000) (noting that the drug in question, “because it is only available by prescription, is an ethical drug.  It is well recognized that the duty an ethical drug manufacturer owes to the consumer is to warn only physicians or others permitted to dispense prescription drugs of any risks or contraindications associated with that drug.”) (citation omitted).  In State v. Purdue Pharma L.P., 2019 WL 2245743 (N.D. Dist. May 10, 2019), the “learned intermediary doctrine” was one reason for rejecting the plaintiff’s causation theory as “attenuated” because they did not “account for the independent actor (i.e. doctors) who stands between [defendant’s] alleged conduct and the alleged harm.”  Id. at *10.

We know of no North Dakota precedent on the learned intermediary rule in the pharmacy, medical device, or biologic contexts.

Ohio

In Ohio, a statute applies the learned intermediary rule to drugs.

An ethical drug is not defective due to inadequate warning or instruction if its manufacturer provides otherwise adequate warning and instruction to the physician or other legally authorized person who prescribes or dispenses that ethical drug for a claimant in question and if the federal food and drug administration has not provided that warning or instruction relative to that ethical drug is to be given directly to the ultimate user of it.

Ohio Rev. Code §2307.76(c).  The statute codified existing Ohio law.  See Howland v. Purdue Pharma, L.P., 821 N.E.2d 141, 146 (Ohio 2004) (“The learned-intermediary doctrine has been adopted and applied by this court.”) (citation omitted); Wagner v. Roche Laboratories, 671 N.E.2d 252, 256 (Ohio 1996) (“A manufacturer of an unavoidably unsafe ethical (prescription) drug is not strictly liable in tort to a consumer who has suffered injury as a result of ingesting that drug where the manufacturer has provided adequate warning to the medical profession.”); Tracy v. Merrell Dow Pharmaceuticals, Inc., 569 N.E.2d 875, 878 (Ohio 1991) (“Where a prescription drug has been prescribed for a patient by the patient’s physician, the manufacturer has been held to discharge its duty to warn if the manufacturer adequately warns the physician.”) (citations omitted); Seley v. G.D. Searle & Co., 423 N.E.2d 831, 839-40 (Ohio 1981) (“It has become a well established rule in such [prescription drug] cases that the manufacturer satisfies his duty to warn of dangers associated with use of the product by providing adequate *203 warnings to the medical profession, and not the ultimate user.”).

The learned intermediary rule applies to medical devices as a matter of Ohio common law.  Vaccariello v. Smith & Nephew Richards, Inc., 763 N.E.2d 160, 164 (Ohio 2002), rejected an argument that the statute’s omission of medical devices meant that the learned intermediary rule did not apply.

[Section] 2307.76(c) . . . does not thereby abrogate the common law. . . .  [T]he Revised Code does not contain a clear statement that the learned intermediary doctrine, a creature of the common law, cannot apply to prescription medical devices.  We stated in Tracy that “[t]he rationale behind [the learned intermediary doctrine] is that the physician stands between the manufacturer and the patient as a learned intermediary. . . .”  This rationale applies equally to prescription medical devices.  Accordingly, we hold that the learned intermediary doctrine applies to prescription medical devices.

Id. at 164 (citations and quotation marks omitted).

White v. Wyeth Laboratories, Inc., 533 N.E.2d 748, 755 (Ohio 1988), applied the Seley rule to a vaccine/biologic.

In Seley, . . . [w]e further held that the manufacturer of a prescription drug satisfies its duty to warn of risks associated with the use of the product by providing adequate warnings to the medical profession and not to the ultimate user.

Id. at 755 (quotation marks omitted).

In the only Ohio case involving pharmacists and the learned intermediary rule, Estate of Mehrer v. Walgreens Specialty Pharmacy, 218 N.E.3d 301 (Ohio App. 2023), the appellate court did not itself apply learned intermediary rule, but “instructed [the trial court] to consider” it on remand.  Id. at 311.

Oklahoma

The Oklahoma Supreme Court has applied the learned intermediary rule to prescription drugs, Edwards v. Basel Pharmaceuticals, 933 P.2d 298 (Okla. 1997), vaccines, Cunningham v. Charles Pfizer & Co., 532 P.2d 1377 (Okla. 1974), and medical devices, Tansy v. Dacomed Corp., 890 P.2d 881, 886 (Okla. 1994), and McKee v. Moore, 648 P.2d 21 (Okla. 1982).

Cunningham recognized the “general rule . . . that in cases involving prescription drugs the drug manufacturer has only a duty to warn the prescribing physician,” but applied the “mass immunization” exception.  Id. at 1381.  McKee rejected an attempt to distinguish medical devices:

[I]n cases involving prescription drugs, the manufacturer has a duty to warn only the prescribing physician.  Appellants contend that the rule is inapplicable because even though an [product] is sold by prescription it is a device rather than a drug.  We are not persuaded by this argument. . . .  The manufacturer’s duty is to warn the physician, who acts as a learned intermediary between the manufacturer and the consumer, because he is in the best position to evaluate the patient’s needs, assess the benefits and risks of a particular therapy, and to supervise its use. . . .  The manufacturer’s duty to warn the ultimate consumer of prescription drugs, or devices, as distinguished from those sold directly to the consumer, is limited to advising the prescribing or treating physician of the drug’s or device’s potential dangers. . . .  Once the physician is warned, the choice of treatment and the duty to explain the risk is incumbent on the physician.

(footnotes and block quotation omitted).  Accord Tansy, 890 P.2d at 886 (holding, in a device case, that “for the warning requirement, . . . Oklahoma has adopted the learned intermediary doctrine”).

Edwards recognized the learned intermediary rule as applicable to prescription drugs.

[T]he “learned intermediary doctrine” . . . Oklahoma has recognized as applicable in prescription drug cases. . . .  The doctrine operates as an exception to the manufacturer’s duty to warn the ultimate consumer, and shields manufacturers of prescription drugs from liability if the manufacturer adequately warns the prescribing physicians of the dangers of the drug.  The reasoning behind this rule is that the doctor acts as a learned intermediary between the patient and the prescription drug manufacturer by assessing the medical risks in light of the patient’s needs. . . .  The doctrine extends to prescription drugs because, unlike over the counter medications, the patient may obtain the drug only through a physician’s prescription, and the use of prescription drugs is generally monitored by a physician.

Id. at 300-01 (citations and block quotation omitted).

Carista v. Valuck, 394 P.3d 253, 259 (Okla. Civ. App. 2016), held that “the duty of [a p]harmacy . . . is limited by the principles and exceptions to the learned intermediary doctrine.”  Id. at 259.

[The p]harmacy argued that this [learned intermediary] principle places sole responsibility with the physician to communicate any matter covered by the learned intermediary doctrine, and not with a pharmacist.  No published Oklahoma case has applied this doctrine in a case involving a pharmacist.  Many other states . . . have adopted the doctrine, with limited exceptions, to shield pharmacists from being required to “second guess” a physician’s medical decisions embodied in an otherwise authorized and legally made prescription.

Id. at 256.  This precedent “conform[ed] to Oklahoma law.  Id. at 257.

Based on the scope of a pharmacist’s practice, it is clear the responsibility of prescribing medication to a patient does not lie with a pharmacist.  Rather, the determination of whether a particular medication is medically necessary for a patient lies with the treating physician or other appropriate individual.

Id. (citation and quotation marks omitted).

Oregon

Oregon was an early adopter of the learned intermediary rule.  In McEwen v. Ortho Pharmaceutical Corp., 528 P.2d 522, 528 (Or. 1974), the court held:

It is well settled . . . that the manufacturer of ethical drugs bears the additional duty of making timely and adequate warnings to the medical profession of any dangerous side effects produced by its drugs of which it knows, or has reason to know. . . .  Although the duty of the ethical drug manufacturer is to warn the doctor, rather than the patient, the manufacturer is directly liable to the patient for a breach of such duty.  The manufacturer’s compliance with this duty enables the prescribing physician to balance the risk of possible harm against the benefits to be gained by the patient’s use of that drug.

Id. at 385-87 (citations and footnote omitted).  Accord Oakeshott v. Lederle Laboratories, 656 P.2d 293, 297 (Or. 1982) (recognizing that “as a prescription drug manufacturer, defendant had an obligation to warn physicians . . . of possible harmful effects of its prescription medicines”) (citation omitted); Vaughn v. G.D. Searle & Co., 536 P.2d 1247, 1248 (Or. 1975) (reaffirming “the duty of a drug manufacturer to provide timely and adequate warnings to the medical profession” in a contraceptive drug case).

However, Oregon passed a product liability statute, effective in 1980, that adopted Restatement §402A and its comments.  Griffith v. Blatt, 51 P.3d 1256, 1260-61 (Or. 2002) (discussing Or. Rev. Stat. §30.920(3)).  Because the learned intermediary rule does not appear in the Second Restatement (although it does in the Third, see, Products Liability §6(c)), the Oregon Supreme Court in Griffith held that “Oregon’s product liability statute does not create a defense to strict liability based on the learned intermediary doctrine.”  Id. at 1262.  Thus, Oregon draws a unique distinction between negligence – where the rule applies – and strict liability – where it does not.

No Oregon appellate court has applied the learned intermediary rule in a medical device case, but several trial courts applying Oregon law have.  Pearson v. Ethicon, Inc., 2021 WL 4498562, at *7 (Mag. D. Or. Aug. 16, 2021) (applying learned intermediary rule to medical device to extent allowed by Griffith), adopted in pertinent part, 2021 WL 4494188 (D. Or. Sept. 30, 2021); Johnson v. Medtronic Inc., 2021 WL 2669560, at *4 (Mag. D. Or. June 10, 2021) (“Defendants had a duty to warn [the surgeon] of the known risks associated with their [device]”), adopted, 2021 WL 2668793 (D. Or. June 29, 2021); Allen v. G.D. Searle & Co., 708 F. Supp. 1142, 1147-48 (D. Or. 1989) (“This court will . . . apply the learned intermediary doctrine in this case” involving an IUD); Jennings v. Baxter Healthcare Corp., 1995 WL 17815190 (Or. Cir. Nov. 6, 1995) (“Implants by definition are placed in the human body by licensed physicians.  There is no reason treat breast implants any differently than other medical devices which require a prescription.”).  The oldest decision still has the most cogent reasoning:

There is no reason to believe that this [learned intermediary] concept applies with any less force to a case like plaintiff’s which involves the use of a prescription device. . . .  The devices are available only through a physician’s prescription  The physician performs an individualized balancing of the benefits and risks to the patient before prescribing the device. . . .  The doctor who prescribes an IUD is no less a “learned intermediary” between manufacturer and patient than was the physician in McEwen. . . .  For this reason I am convinced that Oregon courts would . . . hold . . . that the manufacturer of an IUD has a duty to warn physicians, not patients, of any possible dangers associated with its use.

Steinmetz v. A.H. Robins Co., 1981 WL 768631, at *2 (D. Or. Aug. 27, 1981) (citations omitted).

We are unaware of any Oregon law decision addressing the learned intermediary rule in either a biologic or pharmacy situation).

Pennsylvania

Pennsylvania is another early adopter of the learned intermediary rule.  In Incollingo v. Ewing, 282 A.2d 206, 220 & n.8 (Pa. 1971), a prescription drug case, the Pennsylvania Supreme Court held:

Since the drug was available only upon prescription of a duly licensed physician, the warning required is not to the general public or to the patient, but to the prescribing doctor.  The question, therefore, in this case is whether the warning that was given to the prescribing doctors was proper and adequate.

Id. at 220 (citation omitted).  Accord Baldino v. Castagna, 478 A.2d 807, 812 (Pa. 1984) (“where such drugs are available by prescription only, ‘the warning required is not to the general public or to the patient, but to the prescribing doctor.’”) (quoting Incollingo).  Cf. Lance v. Wyeth, 85 A.3d 434, 457 (Pa. 2014) (“not consider[ing] the wisdom of modifications or exceptions to the [learned intermediary] doctrine” in drug warning cases).

The learned intermediary rule was applied in the pharmacy context in Coyle v. Richardson-Merrell, Inc., 584 A.2d 1383, 1385 (Pa. 1991) (applied to pharmacists):

Since . . . this Court decided Incollingo v. Ewing, it has been clear that when a drug “is available only upon prescription of a duly licensed physician, the warning required is not to the general public or to the patient, but to the prescribing doctor”. . . .  

In arguing that pharmacists have an independent duty to warn of allegedly dangerous characteristics of prescription drugs they dispense, the appellants give scant attention to the rule of Incollingo or its rationale.  Under that rule, information about the risks of medicines is provided to the person who most needs and can best evaluate it − the physician − to be shared with and explained to the patient in the context of his or her individual medical circumstances.  If the manufacturer has no duty to directly warn patients of the risks of drugs, it would indeed be incongruous to hold pharmacists to such a duty in the dispensing of drugs. . . .  Pharmacists, as suppliers, do not freely choose which “products” they will make available to consumers in any given instance, and patients, as consumers, do not freely choose which “product” to buy.  Physicians exercising sound medical judgment act as intermediaries in the chain of distribution, preempting, as it were, the exercise of discretion by the supplier-pharmacist, and, within limits, by the patient-consumer. . . .  While the patient is entitled to know, and a doctor has a duty to inform the patient, of any dangers or side effects associated with a drug recommended for treatment, we see no sound reason for imposing on pharmacists the duty to supply information about the risks of drugs that have already been prescribed.  On the contrary, such a rule would have the effect of undermining the physician-patient relationship by engendering fear, doubt, and second-guessing.

Id. at 1385-86 (block quote omitted).  See Makripodis v. Merrell Dow Pharmaceuticals, Inc., 523 A.2d 374, 378 (Pa. Super. 1987) (applying learned intermediary rule to pharmacists pre-Coyle).

As for medical devices, Pennsylvania’s intermediate courts have applied the rule to these products several times. 

Under the learned intermediary doctrine . . . a manufacturer will be held liable only where it fails to exercise reasonable care to inform the one for whose use the product is supplied of the facts which make the product likely to be dangerous.  The intended “user” in a case involving a prescription drug or device is, of course, the prescribing physician.

Rosci v. AcroMed, Inc., 669 A.2d 959, 969 (Pa. Super. 1995) (citations omitted). 

[Plaintiffs’] argument presents only a facile conclusion that because existing cases have not applied the learned intermediary doctrine in that context, there exists no basis for its application here.  We find this rationale unsubstantiated and unconvincing.  To the extent that our court’s have previously applied the doctrine in relation to prescription drugs, we find no compelling reason why it may no be so applied here.

Creazzo v. Medtronic, Inc., 903 A.2d 24, 32 (Pa. Super. 2006).  Accord Brecher v. Cutler, 578 A.2d 481, 485 (Pa. Super. 1990) (IUD case; “A manufacturer will be held liable only if he fails to exercise reasonable care to inform the one for whose use the product is supplied of the facts which make it likely to be dangerous.”) (citation omitted).

The Third Circuit applied Pennsylvania’s learned intermediary rule to a vaccine/biologic in Mazur v. Merck & Co., 964 F.2d 1348, 1355-57 (3d Cir. 1992) (also holding that a nurse can be a learned intermediary).  See Lennon v. Wyeth-Ayerst Laboratories, Inc., 2001 WL 755944, at *2 (Pa. Super. June 14, 2001) (“the learned intermediary rule exists specifically because certain drugs are available only upon prescription, which only a licensed physician may provide, or, as in the case of the vaccine, upon administration by a health care professional at a doctor’s direction”) (non-precedential).

Puerto Rico

We could not find (at least in the English translations) any Puerto Rico territorial/commonwealth court decisions involving the learned intermediary rule.  Federal court cases applying Puerto Rico law have adopted the learned intermediary rule.  Guevara v. Dorsey Laboratories, Division of Sandoz, Inc., 845 F.2d 364 (1st Cir. 1988), held

The duty to warn in general is limited to hazards not commonly known to the relevant public. . . .  The courts have recognized this principle in their description of the scope of a drug manufacturer’s duty to warn: The warning should be sufficient to appraise a general practitioner as well as the unusually sophisticated medical man of the dangerous propensities of the drug.

Id. at 367 (citation and quotation marks omitted).

The rule has also been applied in Mendez Montes De Oca v. Aventis Pharma, 579 F. Supp.2d 222, 227 (D.P.R. 2008) (“This rule is known as the ‘learned intermediary doctrine’ whereby a prescription drug manufacturer has no duty to warn consumers directly of dangers or risks posed by the use of its product.  Rather, this duty extends exclusively to the prescribing physicians.”) (biologic); Rivera-Adams v. Wyeth, 2010 WL 5072541, at *3 (D.P.R. Dec. 8, 2010) (“[w]hen the product at issue is a prescription drug, the manufacturer’s duty to warn does not run to the user of the drugs directly; instead, the manufacturer has a duty to adequately warn prescribing physicians”) (prescription drug); Pierluisi v. E.R. Squibb & Sons, Inc., 440 F. Supp. 691, 694-95 (D.P.R. 1977) (“the duty of adequate warning by the manufacturer of an ethical drug is discharged by its warning of hazards to doctors”) (prescription drug).  We did not find any medical device or pharmacy learned intermediary cases from Puerto Rico.

Rhode Island

While the Rhode Island Supreme Court has yet to consider the learned intermediary rule, federal courts have consistently predicted that it will adopt the rule.  Greaves v. Eli Lilly & Co., 503 F. Appx. 70, 71 (2d Cir. 2012) (“[W]e conclude that the Rhode Island Supreme Court would likely adopt the learned intermediary doctrine if faced with the question of whether to do so under circumstances similar to these”) (applying Rhode Island law).  Accord Hogan v. Novartis Pharmaceuticals Corp., 2011 WL 1533467, at *10 (E.D.N.Y. April 24, 2011) (“the learned intermediary rule seeks to preserve the doctor-patient relationship and allows the doctor to interpret the dangers involved in taking a drug; a warning to the patient, the rationale suggests, even if practical, could be detrimental as the patient may not properly weigh the drug’s risks against its benefits.”) (applying Rhode Island law).

The same is true of medical devices.  Costa v. Johnson & Johnson, 2023 WL 2662903, at *3 (D.R.I. March 28, 2023), held:

The Rhode Island Supreme Court has not expressly adopted the learned intermediary doctrine. . . .  Here, a number of factors counsel in favor of predicting that the Rhode Island Supreme Court would adopt the learned intermediary doctrine.  First, the Rhode Island Supreme Court has implicitly referenced the doctrine when describing the proximate cause element of a failure to warn claim.  In addition, the Rhode Island Supreme Court frequently relies on the Second and Third Restatements of Torts as a basis for the state’s product liability law.  The learned intermediary doctrine is defined in §388 of the Second Restatement, which the Rhode Island Supreme Court has cited with approval in other contexts.  The doctrine is also defined in §6 of the Third Restatement of Torts: Products Liability, other provisions of which the Rhode Island Supreme Court has cited with approval. . . .  Finally, the Court follows the lead of other federal courts that have predicted that the Rhode Island Supreme Court would likely adopt the learned intermediary doctrine.

Id. at *3 (citations and quotation marks omitted).  Accord Franks v. Coopersurgical, Inc., 722 F. Supp.3d 63 (D.R.I. 2024) (“the Rhode Island Supreme Court would likely adopt the [learned intermediary] doctrine, if given the opportunity, considering its reliance on the Second and Third Restatements of Torts as the basis for the state’s product liability law”) (following Costa).

We found no Rhode Island biologic or pharmacy cases involving the learned intermediary rule.

South Carolina

The South Carolina Supreme Court adopted the learned intermediary rule in Madison v. American Home Products Corp., 595 S.E.2d 493 (S.C. 2004), a “case present[ing] the purely legal issue of whether a pharmacy may be held strictly liable for properly filling a prescription drug in accordance with a physician’s orders.  Id. at 494.  Madison said no:

In addition to the theory that filling a prescription is more of a service than a sale, courts have found no basis to impose strict liability on pharmacists because . . . strict liability is inconsistent with the learned intermediary doctrine, which places the duty to warn on the prescribing physicians, and not pharmacists; the imposition of such duties would force pharmacists to refuse to stock necessary drugs because of risks involved, refuse to use less expensive generic drugs, or second guess the judgment of prescribing physicians.

Id. at 496 (citation and quotation marks omitted).

The Fourth Circuit has consistently applied South Carolina’s learned intermediary rule to prescription drugs and medical devices.  The earliest decisions involved medical devices.  Brooks v. Medtronic Inc., 750 F.2d 1227 (4th Cir. 1984), determined that, “[a]lthough the South Carolina Supreme Court has not addressed the issue, we conclude it would adopt the [learned intermediary] rule, generally accepted and supported by sound policy, restricting the manufacturer’s duty to warn to the prescribing physician.”  Id. at 1231.  This “drug exception,” id., was equally applicable to prescription medical devices.  “[T]he decision to prescribe [this device] involves precisely the sort of individualized medical balancing contemplated by the drug exception.”  Id. at 1232.  

It is plain that [plaintiff’s] claim is governed by the “learned intermediary” doctrine.  Under this doctrine, the manufacturer’s duty to warn extends only to the prescribing physician, who then assumes responsibility for advising the individual patient of risks associated with the drug or device.

Odom v. G.D. Searle & Co., 979 F.2d 1001, 1003 (4th Cir. 1992) (Brooks citation omitted).

But the Fourth Circuit has applied the rule to prescription drugs as well:

[T]he traditional view [is] that manufacturers of drugs and medical devices can discharge their common law duty by giving warnings directed to health-care providers and not to patients.  These healthcare providers act as “learned intermediaries,” using their knowledge, training, and experience to provide the patient with such information as is deemed appropriate under the circumstances so that the patient can make an informed choice as to therapy.  Often, the “learned intermediary” is the patient’s prescribing physician.

Bean v. Upsher-Smith Pharmaceuticals, Inc., 765 F. Appx. 934, 936 (4th Cir. 2019) (citations and quotation marks omitted).

Stratton v. Merck & Co., 2021 WL 5416705 (D.S.C. Nov. 17, 2021), applied the learned intermediary rule in the context of a biologic product.  Id. at *4 (treating defendant’s vaccine as equivalent to a drug for learned intermediary purposes). 

South Dakota

While the South Dakota Supreme Court has not addressed the learned intermediary rule, federal courts have applied it to South Dakota law:

To survive summary judgment, [plaintiffs] must establish a genuine issue of material fact whether an adequate warning would have altered [their prescriber’s] decision to prescribe [the drug].  The learned intermediary doctrine states that adequate warnings to prescribing physicians obviate the need for manufacturers of prescription products to warn ultimate consumers directly.

Schilf v. Eli Lilly & Co., 687 F.3d 947, 949 (8th Cir. 2012) (citations and quotation marks omitted).  Accord McElhaney v. Eli Lilly & Co., 575 F. Supp. 228, 231 (D.S.D. 1983) (“In cases involving prescription drugs the manufacturer must warn the physician, not the patient.”) (citation and quotation marks omitted), aff’d, 739 F.2d 340 (8th Cir. 1984); Yarrow v. Sterling Drug, Inc., 263 F. Supp. 159, 162 (D.S.D. 1967) (“In situations such as this, where the drug is a prescription drug, the manufacturer has a duty to properly warn the doctor of the dangers involved.”) (citations omitted), aff’d, 408 F.2d 978 (8th Cir. 1969).

Sluis v. Ethicon, Inc., 529 F. Supp.3d 1004 (D.S.D. 2021), applied the learned intermediary rule to a medical device.

Under [the learned intermediary] doctrine, a manufacturer of medical devices or pharmaceuticals satisfies its duty to warn by providing the appropriate information to the treating physician.  The treating physician then acts as a learned intermediary between the manufacturer and the patient, obviating the need for the manufacturer to warn the patient directly. . . .  Although [prior decisions] involved a drug manufacturer, [the] reasons for predicting that the Supreme Court of South Dakota would follow the learned intermediary doctrine apply with equal force here.  Thus, this Court predicts that the Supreme Court of South Dakota would follow the learned intermediary doctrine in cases against a designer and manufacturer of medical devices.

Id. at 1010 (discussion of Schilf omitted).  Accord Foster v. Ethicon, Inc., 529 F. Supp.3d 992, 997-98 (D.S.D. 2021) (identical discussion).

We have not seen any South Dakota law decisions that considered the learned intermediary rule in the context of pharmacies or biologics.

Tennessee

The Tennessee Supreme Court adopted the learned intermediary rule in Pittman v. Upjohn Co., 890 S.W.2d 425, 429 (Tenn. 1994).

Under the “learned intermediary doctrine,” makers of unavoidably unsafe products who have a duty to give warnings may reasonably rely on intermediaries to transmit their warnings and instructions.  Physicians are such intermediaries because of the pivotal role they play in the unique system used to distribute prescription drugs. . . .  However, physicians can be learned intermediaries only when they have received adequate warnings.  Thus, the learned intermediary doctrine does not shield a drug manufacturer from liability for inadequate warnings to the physician.

Id. at 429 (citations omitted).

Tennessee’s learned intermediary rule applies to medical devices as well as drugs.

The defendant relied on the defense of learned intermediary.  Under this doctrine, manufacturers of certain medical products may reasonably rely on intermediaries to transmit their warnings and instructions.  This defense is based upon the pivotal role that physicians play in the distribution of prescription products. . . .  Under this doctrine, physicians are the “consumers” who must be warned.

Harden v. Danek Medical, Inc., 985 S.W.2d 449, 451 (Tenn. App. 1998) (citations and quotation marks omitted).  Accord King v. Danek Medical, Inc., 37 S.W.3d 429, 453 (Tenn. App. 2000) (following Harden; “Accordingly, the learned intermediary doctrine applied to the plaintiffs’ allegation of failure to warn, and summary judgment was properly granted.”).

In Laws v. Johnson, 799 S.W.2d 249 (Tenn. App. 1990), the court applied learned intermediary rule principles to an action against a pharmacist, and affirmed summary judgment.

In considering the issue at bar it is necessary to recognize there is one body of the law relating to “proprietary or patent medicine” and the other relating to “ethical drugs” dispensed only by prescription.  In dispensing “proprietary or patent” medicine all warnings relating to the use of the drug must be given to the consumer of the drug.  In dispensing “ethical or prescription” drugs all warnings relating to the use of the drug must be given to the doctor or physician prescribing the drug.

Id. at 251 (citation omitted).  Significantly, the Tennessee Supreme Court in Pittman quoted and adopted as its own Laws’ statement of the learned intermediary rule.  890 S.W.2d at 429.  Cf. Johnson v. Settle, 2001 WL 585093, at *8 (Tenn. App. June 1, 2001) (learned intermediary rule protects medical supply company in suit over delivery correctly-labeled medical product).

We found no Tennessee learned intermediary decisions involving biologic products.

Texas

The Texas Supreme Court emphatically endorsed the learned intermediary rule in Centocor, Inc. v. Hamilton, 372 S.W.3d 140 (Tex. 2012), a prescription drug case.  Centocor summarized its holdings here:

Under the learned intermediary doctrine, the manufacturer of a pharmaceutical product satisfies its duty to warn the end user of its product’s potential risks by providing an adequate warning to a “learned intermediary,” who then assumes the duty to pass on the necessary warnings to the end user.  In this case, we consider the applicability of the learned intermediary doctrine to a patient’s claims against a prescription drug manufacturer. . . .  We hold that the doctrine generally applies within the context of a physician-patient relationship and allows a prescription drug manufacturer to fulfill its duty to warn end users of its product’s potential risks by providing an adequate warning to the prescribing physician. . . .  Although the patient alleged various common law causes of action, all of the patient’s claims turn on the prescription drug manufacturer’s failure to warn. Therefore, the learned intermediary doctrine applies to all of the patient’s claims.

Id. at 142-43.  See also Id. at 154-59, 164-66, 168-69 (detailed discussion of these issues).  Cf. Humble Sand & Gravel, Inc. v. Gomez, 146 S.W.3d 170, 190-91 (Tex. 2004) (applying learned intermediary rule in non-medical context); Alm v. Aluminum Co. of America, 717 S.W.2d 588, 590-92 (Tex. 1986) (same).

Texas appellate courts have routinely applied the learned intermediary rule in the medical context.  Verticor, Ltd. v. Wood, 509 S.W.3d 488, 495 (Tex. App. 2015) (“the ‘learned intermediary’ doctrine may limit the duty of a manufacturer or seller of prescription drugs or medical devices to warn end users of the product’s dangerous propensities”); Seifried v. Hygenic Corp., 410 S.W.3d 427, 432 (Tex. App. 2013) (“The prescribing doctor stands as a learned intermediary between the manufacturer and the consumer.”); Ethicon Endo-Surgery, Inc. v. Meyer, 249 S.W.3d 513, 516 (Tex. App. 2007) (applying learned intermediary causation, as the “independent knowledge doctrine,” in medical device case); Guzman v. Synthes (USA), 20 S.W.3d 717, 720 n.2 (Tex. App. 1999) (“where, as here, the product is meant only for administration by a physician, the physician is integrally involved in deciding what type of medical device to use on the patient, and the physician is in a better position than the patient to understand the dangers and propensities of the possible devices, the supplier satisfies its duty by warning and instructing the treating physician”) (citation omitted); Bean v. Baxter Healthcare Corp., 965 S.W.2d 656, 663 (Tex. App. 1998) (“we see no basis for distinguishing [prescription devices] from prescription drugs for purposes of applying the doctrine; in both instances, the product is manufactured for administration only by a physician or other authorized person.”; “The doctor stands as a learned intermediary between the manufacturer and the consumer.”); In re DePuy Orthopaedics, Inc., Pinnacle Hip Implant Products Liability Litigation, 888 F.3d 753, 774 (5th Cir. 2018) (“[u]nder the learned-intermediary . . . doctrine, which Texas applies in medical products liability actions, the manufacturer  satisfies its duty to warn the end user of its product’s potential risks by providing an adequate warning to a ‘learned intermediary’”) (quotation marks and footnote omitted); Porterfield v. Ethicon, Inc., 183 F.3d 464, 467-68 (5th Cir. 1999) (“The learned intermediary doctrine applies in medical products liability actions in Texas.”) (citation omitted); In re Norplant Contraceptive Products Litigation, 165 F.3d 374, 379 (5th Cir. 1999) (“as long as a physician-patient relationship exists, the learned intermediary doctrine applies”).

Morgan v. Wal-Mart Stores, Inc., 30 S.W.3d 455, 467 (Tex. App. 2000), applied the learned intermediary rule to shield pharmacists from an independent duty to warn of dangers associated with prescription drugs.

[I]n light of the learned intermediary doctrine, which we find applicable to the relationship among physician, patient, and pharmacist, we hold that pharmacists have no generalized duty to warn patients of potential adverse reactions to prescription drugs absent some special circumstances not present here.  We do not imply that pharmacists may not warn patients of potential adverse reactions or dangerous side effects; we merely hold that pharmacists are not legally obligated to do so.

Id. at 469.

The learned intermediary rule also applies to Texas prescription biologic cases.  Hurley v. Lederle Laboratories, 863 F.2d 1173 (5th Cir. 1988), applied it to a vaccine.

Next we consider whether the doctrine of the learned intermediary applies in this case.  It is clear that this doctrine applies when a patient receives a drug or vaccination through a doctor who weighs the risks and benefits, and makes the decision to administer it.  In such a case, the fact that the manufacturer has adequately warned the prescribing physician will protect it from liability to the patient for failure to warn.

Id. at 1178.  A prior vaccine case under Texas law likewise recognized the learned intermediary rule.  Reyes v. Wyeth Laboratories, 498 F.2d 1264, 1276 (5th Cir. 1974) (“in selling prescription drugs [defendants] are required to warn only the prescribing physician, who acts as a ‘learned intermediary’ between manufacturer and consumer”) (footnote omitted).  Reyes, however, held that an exception to the rule applied.  Id. at 1277.

Utah

The Utah Supreme Court first recognized the learned intermediary rule in Barson v. E.R. Squibb & Sons, Inc., 682 P.2d 832 (Utah 1984), holding that “[t]he manufacturer of ethical drugs has the duty of making timely and adequate warnings to the medical profession of any dangerous side effects produced by its drugs of which it knows or has reason to know.  The manufacturer is directly liable to the patient for the breach of such duty.”  Id. at 835 (footnotes omitted).

Utah’s highest court has also applied the learned intermediary rule twice in pharmacy cases. 

Under this rule, manufacturers of prescription drugs have a duty to warn only the physician prescribing the drug, not the end user or patient. . . .  It is the physician who is best situated to weigh the potential risks associated with a prescription drug against the possible benefits of the drug and the unique needs and susceptibilities of each patient.  The physician thus has the ability to combine medical knowledge and training with an individualized understanding of the patient’s needs, and is the best conduit for any warnings that are deemed necessary.  Many courts extend the learned intermediary rule to exempt pharmacists from strict products liability under a failure to warn theory.

Schaerrer v Stewart’s Plaza Pharmacy, Inc., 79 P.3d 922, 928-29 (Utah 2003) (citations omitted).

We [have] adopted the learned intermediary rule for purposes of exempting pharmacists from strict products liability, noting the classic concerns that the rule is intended to address.  We also made it clear, however, that the rule made sense in the context of a highly regulated distribution system for prescription drugs:  So long as a pharmacist’s ability to distribute prescription drugs is limited by the highly restricted, FDA-regulated drug distribution system in this country, and a pharmacist cannot supply a patient with prescription drugs without an intervening physician’s prescription, we will not impose a duty upon the pharmacist to warn of the risks associated with the use of prescription drugs.

Downing v. Hyland Pharmacy, 194 P.3d 944, 946 (Utah 2008) (Schaerrer citation and quotation marks omitted).  In Jensen v. Walgreen Co., 579 P.3d 305 (Utah 2025), the court reiterated the general applicability of the learned intermediary rule to pharmacists, id. at 311, but identified exceptions for “patient-specific risk[s] or . . . obvious error[s] on the face of the prescription.”  Id. at 313,

A nonprecedential federal appellate decision reference Utah’s learned intermediary rule in a medical device case in Tingey v. Radionics, 193 F. Appx. 747, 757 n.4 (10th Cir. 2006) (“Utah follows the ‘learned intermediary doctrine,’ whereby it is the manufacturer’s duty to warn the doctor of the dangers associated with a dangerous drug, rather than the patient.  Courts have applied this doctrine to claims involving medical devices, and we assume Utah would do so as well.”) (citations omitted).  So have several trial courts.  See In re Davol, Inc./C.R. Bard, Inc., Polypropylene Hernia Mesh Products Liability Litigation, 2020 WL 5223363, at *16 (S.D. Ohio Sept. 1, 2020) (“this Court will apply the learned intermediary doctrine to Plaintiff’s failure to warn claims”); In re Wright Medical Technology, Inc., Conserve Hip Implant Products Liability Litigation, 127 F. Supp.3d 1306 (N.D. Ga. 2015) (“the person who receives a medical device or to whom it is applied, is prescribed the device by a physician . . ., and it is the physician upon whom the user, or patient, relies to advise of warnings and risks.  It is from this practical reality in the doctor-patient relationship that the learned intermediary doctrine developed.”); Flandro v. Boston Scientific Corp., 2015 WL 5842823, at *5 (S.D.W. Va. Oct. 6, 2015); (“Utah courts adhere to the learned intermediary doctrine”; “Utah courts would likewise apply the learned intermediary doctrine to failure to warn claims arising out of the use of medical devices.”) (all applying Utah law).

Christison v. Biogen Idec Inc., 199 F. Supp. 3d 1315, 1320 (D. Utah 2016) , applied the learned intermediary rule to a biologic medication.

The learned intermediary doctrine has been adopted in Utah. . . .  [B]ecause the physician is in the best position to combine medical knowledge and training with an individualized understanding of the patient’s needs[,] . . . under Utah law, a drug manufacturer’s duty is to give timely, adequate, complete, and appropriate warnings to the prescribing physician such that the physician can understand possible side effects and prepare a suitable prescription program for a patient.

Id. at 1319-20 (quotation marks and footnotes omitted); accord Christison v. Biogen Idec Inc., 2014 WL 7261300 (D. Utah Dec. 18, 2014):

These allegations that Defendants had a duty to provide warnings directly to the patient . . . are incorrect and therefore they are stricken.  While it is true that under the learned intermediary doctrine a drug manufacturer may be liable directly to a patient if the manufacturer fails to adequately warn the prescribing physician, the manufacturer has no duty to directly warn a patient.

Id. at *7 (footnote omitted).

Vermont

Vermont lacks any appellate authority addressing the learned intermediary rule.  Several trial courts have applied the rule to Vermont law in various contexts.  In a pharmacy case, Baker v. University of Vermont, 2005 WL 6280644 (Vt. Super. May 5, 2005), held:

While apparently never explicitly treated by our Supreme Court, we consider the so-called “learned intermediary doctrine” adopted in a majority of jurisdictions to be of significant dispositive effect in determining the present claims.  The learned intermediary doctrine, first recognized in 1966, initially stood for the proposition that a prescription drug manufacturer had a had a duty to warn of possible side effects in some patients only to a purchasing doctor, the learned intermediary between the manufacturer and patient, and not directly to the patient.  The majority of jurisdictions have expanded this approach to cover pharmacists as well. . . .  [A] pharmacist has no duty to warn patients or doctors under the circumstances presented here.

Id. at ?? (citations omitted).

The same is true in federal court.  Leavitt v. Ethicon, Inc., 524 F. Supp.3d 360 (D. Vt. 2021), a medical device case, “predict[ed that the Vermont Supreme Court is likely to adopt the learned intermediary doctrine for three reasons”:

First, where Vermont law is undeveloped, the Vermont Supreme Court frequently looks to the Restatement for guidance . . ., and the restatement “has adopted the learned intermediary doctrine.”. . . .  Second, forty-eight states have adopted, or a federal court has predicted the state’s highest court would adopt, the learned intermediary doctrine. . . .  and third, the learned intermediary doctrine reflects the realities of patient consultations and identifies the best source of information regarding the risks and benefits of a particular device or procedure for a particular patient.

Id. at 368-69 (footnotes omitted).  A couple of other Vermont decisions discussed the learned intermediary rule at some length, but avoided deciding the issue.  See Drake v. Allergan, Inc., 63 F. Supp.3d 382, 390 (D. Vt. 2014); Kellogg v. Wyeth, 762 F. Supp.2d 694, 700 (D. Vt. 2010) (both prescription drug cases).

Virginia

The Virginia Supreme Court recognized the learned intermediary rule in Pfizer, Inc. v. Jones, as an “elementary principle[] of law.”  272 S.E.2d 43, 44 (Va. 1980).  “[I]t is the general rule that the duty of the drug manufacturer is to warn the physician who prescribes the drug in question.”  Id. (citation omitted).  Accord Stanback v. Parke, Davis & Co., 657 F.2d 642, 644 (4th Cir.1981) (“the well-settled rule is that the duty an ethical drug manufacturer owes to the consumer is to warn only physicians (or other medical personnel permitted by state law to prescribe drugs) of any risks or contraindications associated with that drug”; “we assume that the Virginia Supreme Court would follow the general rule”) (citations omitted).

The Fourth Circuit agreed in a medical device case.  Talley v. Danek Medical, Inc., 179 F.3d 154, 162-63 (4th Cir. 1999). 

The learned intermediary doctrine provides an exception to the general rule imposing a duty on manufacturers to warn consumers about the risks of their products.  For products requiring prescription or application by physicians, the doctrine holds that a manufacturer need only warn doctors and not consumers. The doctrine is based on sound policy considerations. . . .  For physician-prescribed drugs and medical devices, the physician is in the best position to understand the patient’s needs and assess the risks and benefits of a particular course of treatment. . . .  In addition, practical realities support the learned intermediary doctrine because it is virtually impossible in many cases for a manufacturer to directly warn each patient. . . .

Accordingly, in circumstances where (1) ethical drugs or medical devices that can be prescribed or installed only by a physician are involved and (2) a physician prescribes the drug or installs the medical device after having evaluated the patient, the manufacturer of the drug or device owes the patient only the duty to warn the physician and to provide the physician with adequate product instructions.

Id. at 162-63 (citations and quotation marks omitted). 

Similarly, the Fourth Circuit applied the learned intermediary rule in a Virginia vaccine/biologic case − holding, in Abbot v. American Cyanamid Co., 844 F.2d 1108 (4th Cir. 1988), that “[w]ith prescription drugs, . . . the duty is to warn the physician administering the drug.”  Id. at 1115 (citing Stanback).

A Virginia federal court applied it to a veterinary drug in Knapp v. Zoetis Inc., 2022 WL 989015, at *6 (E.D. Va. March 31, 2022).  We know of no pharmacy cases that have considered the learned intermediary rule under Virginia law.

Washington

Washington is another learned intermediary rule early (and often) adopter, starting with Terhune v. A.H. Robbins Co., 577 P.2d 975, 978 (Wash. 1978).  In Terhune, a medical device decision, the Washington Supreme Court held:

[I]t has become a well-established rule that in such cases, the duty of the manufacturer to warn of dangers involved in use of a product is satisfied if he gives adequate warning to the physician who prescribes it.  The reasons for this rule should be obvious.  Where a product is available only on prescription or through the services of a physician, the physician acts as a “learned intermediary” between the manufacturer or seller and the patient. It is his duty to inform himself of the qualities and characteristics of those products which he prescribes for or administers to or uses on his patients, and to exercise an independent judgment, taking into account his knowledge of the patient as well as the product.

Id. at 978 (citations omitted).  And, yes, the rule applied to prescription devices as well as drugs:

While recognizing the efficacy of this rule as applied to prescription drugs, the plaintiffs question its applicability to devices. . . .  We do not see this as a significant distinction. . . .  Certainly the insertion of the [device] requires a physician’s services, his knowledge and his skill. While the physician does not make the final choice but leaves that to the patient, he advises the patient with respect to the advantages and disadvantages of various choices, as was done in this case, and it is he who supplies and inserts the device. . . .  The fact that the patient makes the final choice . . . does not constitute a distinction which makes the general rule inapplicable. . . .  In any such situation which may come to mind, the patient is expected to look to the physician for guidance and not to the manufacturer of the products which he may use or prescribe in the course of treatment.

Id.  Taylor v. Intuitive Surgical, Inc., 389 P.3d 517, 525 (Wash. 2017), held “although the manufacturer has a duty to warn patients of product risks, it can satisfy this duty by warning the doctor (the learned intermediary), who then takes on the responsibility of communicating those warnings to the patient”) (citation omitted).  Cf. Accord Rublee v. Carrier Corp., 428 P.3d 1207, 1216-17 (Wash. 2018) (“[I]n the pharmaceutical or medical device context . . . the ’learned intermediary’ doctrine applies.  Under the learned intermediary doctrine, a manufacturer of certain medical products, obtainable solely through the services of a physician, fulfills its duty to warn when it gives adequate warning to the physician who must prescribe the product.”).

In McKee v. American Home Products Corp., 782 P.2d 1045 (Wash. 1989), the Washington high court applied the rule to pharmacists.  The learned intermediary rule was “closely related” to pharmacy warning liability.  Id. at 1049.

The relationship between the physician-patient-manufacturer applies equally to the relationship between the physician-patient and pharmacist. In both circumstances the patient must look to the physician, for it is only the physician who can relate the propensities of the drug to the physical idiosyncrasies of the patient. . . . Neither manufacturer nor pharmacist has the medical education or knowledge of the medical history of the patient which would justify a judicial imposition of a duty to intrude into the physician-patient relationship.  In deciding whether to use a prescription drug, the patient relies primarily on the expertise and judgment of the physician. . . .  The physician is not required to disclose all risks associated with a drug, only those that are material.  It is apparent that a pharmacist would not be qualified to make such a judgment as to materiality. . . .  Requiring the pharmacist to warn of potential risks associated with a drug would interject the pharmacist into the physician-patient relationship and interfere with ongoing treatment.  We believe that duty, and any liability arising therefrom, is best left with the physician.  A majority of other jurisdictions that have addressed the issue have likewise refused to impose a duty to warn on the pharmacist.

Id. at 1050 (citations omitted).  Further, mandating non-physicians to provide direct warning duties would be disruptive and dangerous.

A physician may often have valid reasons for deviating from the drug manufacturer’s recommendations based on a patient’s unique condition.  The duty which [plaintiff] urges would result in the pharmacist second guessing numerous prescriptions to avoid liability.  This would not only place an undue burden on pharmacists, but would likely create antagonistic relations between pharmacists and physicians. . . .  Moreover, unnecessary warnings to the patient could cause unfounded fear and mistrust of the physician’s judgment, jeopardizing the physician-patient relationship and hindering treatment.

Id. at 1053-54 (block quotation omitted).

The Washington Supreme Court has gotten around to applying the learned intermediary rule in prescription drug cases as well.  First, in Washington State Physicians Insurance Exchange & Ass’n v. Fisons Corp., 858 P.2d 1054, 1061 (Wash. 1993).

[I]n examining the nature of the relationship between a drug manufacturer, a prescribing physician and a patient, it is the physician who compares different products, selects the particular drug for the ultimate consumer and uses it as a tool of his or her professional trade.  Under the learned intermediary doctrine, a drug company fulfills its duty by giving warnings regarding prescription drugs to the physician rather than to the patient.  This unique relationship results in the physician being comparable to the ordinary consumer in other settings.

Id. at 1061 (footnote omitted).

Most recently, the rule received a ringing endorsement in Dearinger v. Eli Lilly & Co., 510 P.3d 326 (Wash. 2022):

In the context of prescription drugs, the learned intermediary doctrine provides the manufacturer satisfies its duty to warn the patient of the risks of its product where it properly warns the prescribing physician.  In other words, the manufacturer’s duty to provide warnings to patients transfers to the doctor, who is in a better position to communicate them to the patient.

The learned intermediary doctrine has been a fixed part of Washington law since this court adopted it in Terhune in 1978. Courts applying the learned intermediary doctrine have done so without recognizing an exception.  Indeed, we have consistently reiterated [the] central principle that a manufacturer satisfies its duty to warn patients of product risks by warning the prescribing physician, who then takes on the responsibility of communicating those warnings to the patient. . . .  [N]ot only is the learned intermediary doctrine a fixed part of Washington law, it is also universally followed across the country.

Id. at 329 (citations and quotation marks omitted).  Accord Young v. Key Pharmaceuticals, Inc., 922 P.2d 59, 63 (Wash. 1996) (“while a manufacturer has a duty to warn about unavoidably unsafe products, where the product can be sold only under prescription, the duty to warn runs only to the physician, not to the ultimate consumer”) (citation omitted).

Finally, the learned intermediary rule was extended to biologics in Rogers v. Miles Laboratories, Inc., 802 P.2d 1346, 1353 (Wash. 1991) (quoting and following Terhune and McKee in blood product case).

West Virginia

West Virginia has the dubious distinction of being the only state where the learned intermediary rule was initially rejected by that state’s highest court.  See Johnson & Johnson Corp. v. Karl, 647 S.E.2d 899, 913-14 (W. Va. 2007).  Karl was never applied to medical device cases.  E.g., Smallridge v. Johnson & Johnson, 2022 WL 1417313, at *3 (N.D.W. Va. Jan. 31, 2022) (Karl does not foreclose the application of the learned intermediary doctrine in cases involving a medical device rather than a drug” (citation and quotation marks omitted); accord Sutphin v. Ethicon Inc., 2020 WL 2517237, at *3 (S.D.W. Va. May 15, 2020) (same).

Shortly thereafter, the West Virginia legislature acted, and reversed Karl. 

(a) A manufacturer or seller of a prescription drug or medical device may not be held liable in a product liability action for a claim based upon inadequate warning or instruction unless the claimant proves, among other elements, that:

(1) The manufacturer or seller of a prescription drug or medical device acted unreasonably in failing to provide reasonable instructions or warnings regarding foreseeable risks of harm to prescribing or other health care providers who are in a position to reduce the risks of harm in accordance with the instructions or warnings; and

(2) Failure to provide reasonable instructions or warnings was a proximate cause of harm.

(b) It is the intention of the Legislature in enacting this section to adopt and allow the development of a learned intermediary doctrine as a defense in cases based upon claims of inadequate warning or instruction for prescription drugs or medical devices.

W. Va. Stat. §55-7-30 (emphasis added).

The Supreme Court of Appeals of West Virginia has recognized the legislature’s adoption of the learned intermediary rule.  McNair v. Johnson & Johnson, 818 S.E.2d 852, 865 (W. Va. 2018); J.C. v. Pfizer, Inc., 814 S.E.2d 234, 238 n.9 (W. Va. 2018).  The statute was effective May 17, 2016 and is not retroactive.  J.C., 814 S.E.2d at 238 n.9.

While there have been no West Virginia pharmacy cases since the statute was enacted, the statute reflects the state’s “long-standing restriction of products liability to the manufacturer and seller of the allegedly injury-causing product.”  McNair, 818 S.E.2d at 866.  Thus, the learned intermediary rule has been applied under West Virginia law as a “barrier to imposing a duty [against other third-party warning claims] where the independent medical practitioners assumed ultimate responsibility for advising patient.”  City of Charleston v. Joint Comm’n, 473 F. Supp.3d 596, 624 (S.D.W. Va. 2020) (barring suit against medical accreditation organization).

We have not found any West Virginia law decision addressing the learned intermediary rule in the context of a biologic product.

Wisconsin

Two Wisconsin intermediate appellate decisions have mentioned, but not addressed, the applicability of the learned intermediary rule.  Kurer v. Parke, Davis & Co., 679 N.W.2d 867, 879 (Wis. App. 2004) (“Although the parties debate how the learned intermediary doctrine affects this appeal, we need not make that determination); Rennick v. Teleflex Medical, Inc., 2022 WL 1016686, at *4 (Wis. App. April 5, 2022) (“We need not address the adoption of this doctrine in Wisconsin”) (unpublished, non-citable), aff’d by equally divided court, 988 N.W.2d 680 (Wis. 2023).

In a medical device case, the Seventh Circuit predicted that Wisconsin would follow the learned intermediary rule.  In re Zimmer Nexgen Knee Implant Products Liability Litigation, 884 F.3d 746 (7th Cir. 2018).

The justification for adopting the learned-intermediary doctrine in cases involving prescription drugs applies even more forcefully in cases involving surgical implants. . . .  [P]atients could conceivably gain access to prescription drugs without their doctor’s assistance, but it is not reasonably conceivable that an individual could obtain and implant a device that requires a trained surgeon without the intervention of a physician.

In short, there is good reason to think that given the opportunity, the Wisconsin Supreme Court would join the vast majority of state supreme courts and adopt the learned-intermediary doctrine for use in defective-warning cases like this one involving a surgical implant.  We predict that the state high court would do so.

Id. at 752 (citation and quotation marks omitted).

Both federal and state trial courts in Wisconsin have followed the learned intermediary rule in prescription drug cases.  Lukaszewicz v. Ortho Pharmaceutical Corp., 510 F. Supp. 961, 963 (D. Wis. 1981) (“As a general rule the courts of this country universally hold that in the case of prescription drugs, the provision of proper warnings to a physician will satisfy the manufacturer’s duty to warn since the patient cannot obtain the drug except through the physician.”) (citations omitted), modified on other grounds, 523 F. Supp. 206 (D. Wis. 1981); Straub v. Berg, 2003 WL 26468454, at *6 (Wis. Cir. Jan. 6, 2003) (“Although Wisconsin courts have not addressed the application of the learned intermediary doctrine, courts of numerous other jurisdictions almost universally hold that in the case of prescription drugs, a manufacturer’s provision of proper warnings to a prescribing physician will satisfy the manufacturer’s duty to warn since the patient cannot obtain the drug except through the physician.”) (citation omitted).  Likewise, a Pennsylvania appellate court applied the rule under Wisconsin law.  Stange v. Janssen Pharmaceuticals Inc., 179 A.3d 45, 57 & n.4 (Pa. Super. 2018).

We have found no Wisconsin pharmacy or biologic cases addressing the learned intermediary rule.

Wyoming

In Rohde v. Smiths Medical, 165 P.3d 433, 438 (Wyo. 2007), the Wyoming Supreme Court noted the applicability of the learned intermediary rule in a medical device case. 

The “learned intermediary” principle generally states that a manufacturer has a duty to adequately warn medical professionals about risks associated with use of healthcare products.  So long as it complies with that obligation, the manufacturer may rely on medical professionals, as learned intermediaries, to properly warn their patients of the risks.

Id. at 436 n.5 (citation omitted).

Federal courts under Wyoming law have applied the rule to drugs.  Thom v. Bristol-Myers Squibb Co., 353 F.3d 848, 851-53 (10th Cir. 2003), pointed out:

Known as the “learned intermediary doctrine,” this doctrine shields manufacturers of prescription drugs from liability where the manufacturer adequately warns a patient’s prescribing physician of the potential risks inherent in the use of the product. . . .  The learned intermediary doctrine derives from §402A of the Restatement (Second) of Torts, which the Wyoming Supreme Court has adopted in its entirety. . . .  [Many] other jurisdictions have adopted the learned intermediary doctrine in prescription medicine cases.

Id. at 851-52 (citations omitted).  Accord Haste v. American Home Products Corp., 577 F.2d 1122, 1125 (10th Cir. 1978) (“the defendant discharged its duty to plaintiffs by the warnings to the veterinarians”) (veterinary drug); Van Dyke v. SmithKline, 2009 WL 10672280, at *6 (D. Wyo. March 27, 2009) (“the Wyoming Supreme Court would likely adopt the ‘learned intermediary’ doctrine”) (drug); Van Dyke v. Glaxo SmithKline, 2009 WL 10672277, at *2 (D. Wyo. April 8, 2009) (same); Jacobs v. Dista Products Co., 693 F. Supp. 1029, 1036 (D. Wyo. 1988) (“Defendants communicated adequate warnings to plaintiff’s prescribing physician. . . .  The drug manufacturer’s liability to plaintiff ended when it imparted adequate warnings to the physician.”) (drug).

There aren’t any Wyoming biologic or pharmacy cases that we know of.

*          *          *          *

And now for some statistics.  First, as to the learned intermediary rule generally, it has been applied by the highest courts, or by statute, in 40 American jurisdictions.  Those states are:  Alabama, Alaska, Arizona, Arkansas, California, Connecticut, Delaware, District of Columbia, Florida, Georgia, Hawai’i, Idaho (non-prescription medical product), Illinois, Kansas, Kentucky, Maryland, Massachusetts, Michigan (sort of), Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Jersey, New York, North Carolina, Ohio, Oklahoma, Oregon (negligence only), Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, West Virginia, and Wyoming.  It has been applied by intermediate state appellate courts in another 4-5 jurisdictions:  Colorado, Indiana, Louisiana, Michigan (definitely), and New Mexico.  The rule’s adoption has been predicted by federal appellate courts in another eight jurisdictions:  Iowa, Maine, New Hampshire, North Dakota, Puerto Rico, Rhode Island, South Dakota, and Wisconsin.  In Vermont – the only jurisdiction without appellate authority – it has been adopted at the trial court level.  Thus, the learned intermediary rule is recognized by precedent in all fifty states, the District of Columbia, and Puerto Rico.

Second, as to prescription medical devices specifically, the learned intermediary rule has been applied by the highest courts, or by statute, in sixteen American jurisdictions, those being:  Alabama, Arizona, California, Connecticut, Delaware, Georgia, Hawai’i, Kansas, Mississippi, New Jersey, Ohio, Oklahoma, Oregon (negligence only), Washington, West Virginia, and Wyoming.  It has been applied by intermediate state appellate courts in another nine jurisdictions:  Colorado, Florida, Louisiana, Michigan, New Mexico, New York, Pennsylvania, Tennessee, and Texas.  Federal appellate courts have applied the learned intermediary rule in another ten jurisdictions:  Indiana, Kentucky, Maine, Massachusetts, Missouri, Nebraska, South Carolina, Utah, Virginia, and Wisconsin.  Trial court decisions in another fifteen jurisdictions also apply the rule to medical devices:  Arkansas, District of Columbia, Idaho, Iowa, Maryland, Minnesota, Montana, Nevada, New Hampshire, North Carolina, North Dakota, Oregon, Rhode Island, South Dakota and Vermont.  That’s a total of 50 jurisdictions (everything except Alaska and Puerto Rico).

Third, the learned intermediary rule has been applied to preclude generalized pharmacy warning duties by the highest courts, or by statute, in thirteen American jurisdictions:  Alabama, Arizona, California, Florida, Illinois, Maryland, Massachusetts, Nevada, Pennsylvania, South Carolina, Utah, and Washington.  Intermediate state appellate courts have applied the rule in another thirteen jurisdictions:  Arizona, Georgia, Indiana, Kansas, Louisiana, Michigan, New Jersey, New York, North Carolina, Ohio, Oklahoma, Tennessee, and Texas.  Federal district courts in another four jurisdictions have applied the rule to pharmacists:  Connecticut, District of Columbia, Kentucky, and Maine.  That comes to 30 jurisdictions.

Fourth, and finally, the learned intermediary rule has applied to biological products (vaccines, blood/tissue, and certain other FDA-approved biologics), with other developments – the federal Vaccine Act (which enforces the learned intermediary rule nationwide), and state blood shield statutes – cutting down on the number of cases.  For biologics, the learned intermediary rule has been applied by the highest courts in eight jurisdictions, specifically Florida, Kansas, Mississippi, Nevada, New Jersey, New Mexico, Ohio, Oklahoma, and Washington.  Another four states’ intermediate courts apply the rule to biologics:  Illinois, Michigan, Missouri, and New Mexico.  Federal appellate courts add seven more states to the count:  California, Idaho, Iowa, Maryland, Pennsylvania, Texas, and Virginia.  Finally, trial courts in another nine jurisdictions have enforced the learned intermediary rule in litigation involving biologics:  Indiana, Kentucky, Massachusetts, Nebraska, New York, North Carolina, Puerto Rico, South Carolina, and Utah.  Despite alternative statutory bases for dismissing biologic cases, that makes a total of 28 jurisdictions with such precedent.