The learned intermediary rule – that prescription medical product warnings are directed to (and written to be understood by) the professional medical personnel who prescribe them – is as close to unanimous as any tort doctrine that we know of.  We keep a running tab on the 50 states, and the rule has support in every state, including 37 highest courts (or statutory adoption).  The learned intermediary rule is so widespread because the policies supporting it are likewise universally recognized.  There are several such supportive policies, but one of the most important is to preserve the institution of the physician-patient relationship.

Direct-to-patient warnings from manufacturers and others in the chain of distribution of prescription medical products would inevitably complicate and disrupt the physician-patient relationship.  Unlike physicians, who tailor their informed consent process to the medical needs of particular patients, remote manufacturers could only provide generalized information – and none at all about off-label uses.  If the law were to require persons other than prescribing physicians to send generalized information directly to patients (assuming that it is even practical to do so, another reason for the rule), that information would inevitably conflict with the patient-specific medical advice that the prescribers themselves are legally and ethically required to provide their patients.

Again, that conflict would inevitably occur with off-label uses, given FDA restrictions on what regulated entities are required to say.  Off-label use remains a significant part of medical practice.  In his 2021 off-label use law review article Bexis reported:

More recent estimates indicate the prevalence of off-label use remains notoriously high among some patient populations.  An estimated twenty-one to fifty percent of all prescriptions are for off-label indications and in some patient groups, this number may exceed eighty percent.  Off-label use is particularly prevalent in oncology and in pediatrics.

James Beck, “Off-Label Use in the Twenty-First Century: Most Myths & Misconceptions Mitigated,” 54 UIC J. Marshall L. Rev. 1, 25-26 (2021) (footnotes and quotation marks omitted).  Two years later a Congressional Research Service report reached essentially the same conclusion. 

In a 2006 study of drug prescribing by office-based physicians, 21% of prescriptions were written for off-label uses.  Of those off-label prescriptions, the study’s authors found that 27% were backed by strong scientific support. . . .  An econometric model from the National Ambulatory Medical Care Survey estimated a 38% rate of off-label use.

Research has shown that more than half of oncology drug use is off-label.  A 2018 study examined 43 FDA-approved cancer drugs and compared their 99 labeled uses with the acceptable uses published by a national compendium Medicare relies on to make coverage decisions.  Of the 451 compendium-accepted uses, 56% were off-label. Of the off-label uses, the authors deemed 91% as “well-accepted off-label use.”

Hassan Sheikh, “Off-Label Use of Prescription Drugs,” at 2-3 (2023) (Canadian information and footnotes omitted).  That’s a lot of physician prescriptions that, but for the learned intermediary rule, would be disrupted by extraneous, but legally required information from FDA-regulated product manufacturers.  And the disruption to the physician-patient relationship that the learned intermediary rule prevents goes far beyond just off-label use situations.

Thus, it’s hardly a surprise that courts have repeatedly referenced damage to the physician-patient relationship as a basis for the learned intermediary rule.  Washington adopted the learned intermediary “primarily for public policy reasons focused on preserving the physician-patient relationship,” Rublee v. Carrier Corp., 428 P.3d 1207, 1217 (Wash. 2018), and that state’s highest court discussed the need for the rule to protect the physician-patient relationship at length in Dearinger v. Eli Lilly & Co., 510 P.3d 326 (Wash. 2022):

Physicians comprehend this complex information in a way the average lay person cannot.  Indeed, the FDA has recognized the information on the prescribers’ label is of “questionable” value when provided directly to patients and “relatively inaccessible to consumers. . . .”  [P]hysicians can give personally tailored warnings to patients in a way manufacturers cannot.  A physician can personalize warnings to a patient based on that patient’s medical history and needs.  “[I]t is only the physician who can relate the propensities of the drug to the physical idiosyncrasies of the patient.”  “A physician possesses the medical training to assess adverse health effects of a medical product and to tailor that assessment to a particular patient.”  Conversely, drug manufacturers cannot create individualized warnings because they do not know consumers’ medical information.  Thus, manufacturers issue broad, complex warnings that must be simplified by a learned intermediary − the physician − before being given to patients.

Dearinger v. Eli Lilly & Co., 510 P.3d 326 (Wash. 2022) (quoting McKee v. American Home Products, Corp., 782 P.2d 1045, 1051 (Wash. 1989), and Ruiz-Guzman v. Amvac Chemical Corp., 7 P.3d 795, 802 (Wash. 2000)) (regulatory citation omitted).  McKee also observed that mandating manufacturer warnings “may confuse and frighten the patient.”  782 P.2d at 1055.

Another state high court discussed the learned intermediary rule’s function to protect the physician-patient relationship extensively in Centocor, Inc. v. Hamilton, 372 S.W.3d 140 (Tex. 2012):

Despite the intricate web of modern healthcare providers and treatments, the bedrock of our healthcare system is the physician-patient relationship, and the ultimate decision for any treatment rests with the prescribing physician and the patient.  As a matter of both necessity and practicality, the duty to warn the patient of the potential risks and possible alternatives to any prescribed course of action rests with the prescribing physician. . . .  [Generalized information from a manufacturer] cannot explain the complex intricacies of the human body or supplant the detailed, interconnected nature of the practice of medicine, which necessitates that an informed intermediary help determine the best course of treatment for a patient’s particular symptoms.  To hold that each healthcare provider owes a separate and individual duty to warn each patient of all possible risks associated with a treatment prescribed by any doctor would . . . undermine the prescribing doctor’s physician-patient relationship. . . .  In most prescription drug contexts, the learned intermediary doctrine applies and the duty to warn the patient rests solely with the prescribing physician.

Id. at 166-67 (citations and footnote omitted).

“[I]mposition of a duty to warn the user directly would interfere with the relationship between the doctor and the patient.”  West v. Searle & Co., 806 S.W.2d 608, 613 (Ark. 1991) (citation omitted).  Plainly, “the highly personal doctor-patient relationship” is one of the “safeguards in place under the learned intermediary doctrine.”  Vitanza v. Upjohn Co., 778 A.2d 829, 845 (Conn. 2001).

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.

Lacy v. G.D. Searle & Co., 567 A.2d 398, 400 (Del. 1989).  The “reasons” for the learned intermediary rule are “obvious” – patients “place primary reliance upon [physician] judgment,” and necessarily “[t]he physician decides what facts should be told to the patient.”  Wooderson v. Ortho Pharmaceutical Corp., 681 P.2d 1038, 1052 (Kan. 1984).  Only doctors know exactly how a drug is being prescribed, and can tailor the informed consent discussion to the relevant risks:

[I]mposing a duty to warn upon the manufacturer would unduly interfere with the physician-patient relationship. . . .  []Since the typical manufacturer’s warning provides a list with scores of potential side effects, no matter how minute the possibility of occurrence, the lay consumer might overreact to such warnings and forego beneficial, or even vital, medical treatment.

Larkin v. Pfizer, Inc., 153 S.W.3d 758, 764 (Ky. 2004) (citations omitted).  See Perez v. Wyeth Laboratories, Inc., 734 A.2d 1245, 1255 (N.J. 1999) (“courts do not wish to intrude upon the doctor-patient relationship”; “warnings that contradict information supplied by the physician will undermine the patient’s trust in the physician’s judgment”) (citation and quotation marks omitted).

The same is true for the learned intermediary rule in cases where plaintiffs seek to impose general duties on pharmacists to provide information direction to patients.  Several state high courts have made this crystal clear, the first being Pennsylvania (in a decision Bexis briefed). 

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.

Coyle v. Richardson-Merrell, Inc., 584 A.2d 1383, 1386 (Pa. 1991).  Massachusetts was next in line:

Physicians, after considering the history and needs of their patients and the qualities of the drug, are required to inform their patients of those side effects they determine are necessary and relevant for patients to know in making an informed decision.  Requiring the manufacturer to provide warnings directly to the consumer would interfere with the doctor-patient relationship.

Cottam v. CVS Pharmacy, 764 N.E.2d 814, 820 (Mass. 2002) (citations omitted).  Other states have followed:

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 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.

Walls v. Alpharma USPD, Inc., 887 So.2d 881, 885 (Ala. 2004) (citation omitted).  Accord Kowalski v. Rose Drugs of Dardanelle, Inc., 378 S.W.3d 109, 120 (Ark. 2011) (“the underlying rationale for applying the learned-intermediary doctrine is to protect the patient-physician relationship by preventing pharmacists from second-guessing the physicians or otherwise interfering with the patient-physician relationship”); Nail v. Publix Super Markets, Inc., 72 So.3d 608, 615 (Ala. 2011) (the learned intermediary rule “sought to prevent, asking the pharmacist to intrude himself or herself into the physician-patient relationship”).

In addition to these high court decisions, numerous other state and federal courts have also recognized preservation of the physician-patient relationship as a key policy behind the learned intermediary rule.  The reasoning in Swayze v. McNeil Laboratories, Inc., 807 F.2d 464 (5th Cir. 1987) (applying Mississippi law), rejecting abandonment of the learned intermediary rule because doctors, allegedly, were not doing their jobs, remains valid today and almost universally applicable:

[W]hat would patients do with this information [a direct to patient warning]?  It might prompt would-be patients to put pressure on their physicians to better supervise, but physicians hardly need more incentive to be non-negligent.  In all likelihood, such warnings would only lead to confusion, and perhaps undermine the physician-patient relationship.  When the physician-patient relationship does exist, as here, we hesitate to encourage, much less require, a drug manufacturer to intervene in it. . . .  A special relationship, between physician and patient . . . receives special protection in law, and, at the same time, creates a great responsibility for every physician. . . .  [I]t is the physicians who have undertaken the responsibility of [performing the relevant medical procedures], and that responsibility cannot be shunted onto, or shared with, drug manufacturers.

Id. at 471.  Many other courts, applying the laws of many other jurisdictions, have recognized the essential role that the learned intermediary rule is intended to play in preserving the physician-patient relationship.

Alabama:  Lansdell v. American Home Products Corp., 1999 WL 33548541, at *5 (N.D. Ala. Oct. 26, 1999), held:

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.  Moreover, to hold otherwise, would require the pharmacist to question the physician’s judgment regarding the appropriateness of each customer’s prescription.  Such a policy, inevitably, would wedge the pharmacist into the relationship between a physician and her or his patient and, thereby, interfere with ongoing treatment.

Id. at *5 (citations and quotation marks omitted).  Accord Orr v. Wyeth-Ayerst Laboratories Co., 1999 WL 33548162, at *2 (Ala. Cir. Aug. 2, 1999) (direct-to-patient warnings are an “interference in the patient-physician relationship [that] can only do more harm than good).

Arkansas:  Bell v. Pfizer, Inc., 716 F.3d 1087, 1097 (8th Cir. 2013) (“[A] duty to warn the user directly would interfere with the relationship between the doctor and the patient.  With respect to the relationship between the patient, the physician, and the pharmaceutical manufacturer, the patient must look to the physician, for it is only the physician who can relate the propensities of the drug to the physical idiosyncracies of the patient.”) (citations and quotation marks omitted) (applying Arkansas law); Kendrick v. Wright Medical Technology, Inc., 2021 WL 3516663, at *6 (E.D. Ark. Aug. 10, 2021) (“imposing such a duty to warn on [the manufacturer] would interfere with the relationship between [plaintiff’s surgeon] and [plaintiff]”) (citation and quotation marks omitted); Stube v. Pfizer Inc., 446 F. Supp. 3d 424, 440 (W.D. Ark. 2020) (following West; “requiring drug manufacturers to directly warn the ultimate drug consumer would interfere with the doctor/patient relationship because patients rely on their doctors’ expertise in selecting and using drugs”); Kohl v. American Home Products Corp., 78 F. Supp. 2d 885, 890 (W.D. Ark. 1999) (courts “have been cautious in placing a duty to warn of potential side effects on a pharmacy because such a duty would interfere with the physician-patient relationship”).

California:  Plenger v. Alza Corp., 13 Cal. Rptr. 2d 811, 819 n.6 (Cal. App. 1992):

The rationale of the [learned intermediary] rule is:  [that] The doctor is intended to be an intervening party in the full sense of the word.  Medical ethics as well as medical practice dictate independent judgment, unaffected by the manufacturer’s control, on the part of the doctor. . . .  Were the patient to be given the complete and highly technical information on the adverse possibility associated with the use of the drug, he would have no way to evaluate it, and in his limited understanding he might actually object to the use of the drug, thereby jeopardizing his life.

(quoting Carmichael v. Reitz, 95 Cal. Rptr. 381, 400 (Cal. App. 1971)); Saavedra v. Eli Lilly & Co., 2013 WL 3148923, at *2 (C.D. Cal. June 13, 2013) (“Requiring the manufacturer to provide warnings directly to the consumer would interfere with the doctor-patient relationship.”) (applying California, Massachusetts and Missouri law); Regwan v. Reagan, 2020 WL 7862818, at *4 (Cal. Super. Nov. 5, 2020) (“Plaintiff’s allegations that a device manufacturer owes a duty to supervise and intervene in the provision of medical care cannot be reconciled with California’s licensing scheme or the learned intermediary doctrine and its underlying rationale.  To impose such a duty would place a medical device manufacturer in the middle of the doctor-patient relationship.”); Russo v. Safeway, Inc., 2006 WL 4114000 (Cal. Super. Jan. 3, 2006) (“[T]he rationale for applying the doctrine to pharmacists is compelling.  To impose such a duty to warn on the pharmacist would be to place the pharmacist in the middle of the doctor-patient relationship”.) (footnote omitted).

Connecticut:  DiVincenzo v. Molinaro, 2022 WL 17102332, at *2 (Conn. Super. Nov. 2, 2022) (“To impose a duty to warn on the pharmacist, however, would be to place the pharmacist between the physician who, having prescribed the drug presumably knows the patient’s present condition as well as his or her complete medical history, and the patient. Such interference in the patient-physician relationship can only do more harm than good.”) (citation and quotation marks omitted); Lynch v. State, 2018 WL 2207813, at *4 (Conn. Super. April 17, 2018). (analogizing sperm bank to pharmacist; “physicians have more knowledge than pharmacists about their patients’ needs and proclivities.  Holding otherwise would put pharmacists between the physician-patient relationship.”); Deed v. Walgreen Co., 927 A.2d 1001. 1004 (Conn. Super. 2007) (“To impose a duty to warn on the pharmacist would be to place the pharmacist in the middle of the doctor-patient relationship, without the physician’s knowledge of the patient.”) (citation and quotation marks omitted) (emphasis original).

Florida:  Buckner v. Allergan Pharmaceuticals, Inc., 400 So.2d 820, 823-24 (Fla. App. 1981) (purported physician failures to warn do not affect the learned intermediary rule; “extent of disclosure is a matter of medical judgment”; “failure to do so in a particular instance should not give rise to a duty in the manufacturer”); Pringle v. Johnson & Johnson, 2020 WL 4501834, at *3 n.5 (S.D. Fla. Jan. 30, 2020) (“[w]arnings directly from the manufacturer to the patient can undermine the doctor-patient relationship”); Labzda v. Purdue Pharma, L.P., 292 F. Supp.2d 1346, 1355 (S.D. Fla. 2003) (“Florida law does not impose a duty on the defendants to interfere with the physician-patient relationship”).

Georgia: Williams v. American Medical Systems, 548 S.E.2d 371, 375 (Ga. App. 2001) (“any information supplied to [plaintiff] by [the manufacturer] regarding dangers associated with the device could compromise the doctor-patient relationship”); Lance v. American Edwards Laboratories, 452 S.E.2d 185, 187 (Ga. App. 1994) (“any information supplied to [plaintiff] by defendants regarding dangers associated with use of the [device] may have compromised the doctor-patient relationship and thus impaired the best medical treatment for [plaintiff’s] chronic condition”); Walker v. Jack Eckerd Corp., 434 S.E.2d 63, 67 (Ga. App. 1993) (learned intermediary rule reflects “the need for preserving, without interference of third parties, a trusted physician-patient relationship”); Ellis v. C.R. Bard, Inc., 311 F.3d 1272, 1280 (11th Cir. 2002) (quoting and following Lance); Ingram v. Mylan Pharmaceuticals, Inc., 2009 WL 10665022, at *4 (N.D. Ga. Nov. 12, 2009). (“Considering the reality and practicality of the doctor and patient relationship, the learned intermediary doctrine developed in Georgia.”).

Illinois:  Urbaniak v. American Drug Stores, LLC, 126 N.E.3d 561, 567 (Ill. App. 2019) (“the learned intermediary doctrine dictates that pharmacists stay out of the physician-patient relationship”).  The same court made same point at greater length in Kennedy v. Medtronic, Inc., 851 N.E.2d 778 (Ill. App. 2006):

[A] central aspect of the learned intermediary doctrine . . . is that a licensed physician . . . has the knowledge of his patient’s medical history and background, and, therefore, he is in a better position, utilizing his medical judgment, to determine a patient’s needs and what medical care should be provided.  It would be unreasonable, and potentially harmful, to require a [device manufacturer’s representative] to delay or prevent a medical procedure simply because she believes the setting is not appropriate or the doctor is unqualified.  To hold otherwise would place a medical device manufacturer . . . in the middle of the doctor-patient relationship.

Id. at 786.  The same reasoning was also made, as to a pharmacist, in Fakhouri v. Taylor, 618 N.E.2d 518 (Ill. App. 1993):

Determining which medication is to be utilized in any given case requires an individualized medical judgment, which, in our opinion, only the patient’s physician can provide.  That physician, having prescribed the drug, presumably knows the patient’s current condition, as well as the patient’s complete medical history.  To impose a duty to warn on the pharmacist would be to place the pharmacist in the middle of the doctor-patient relationship, without the physician’s knowledge of the patient.

Id. at 521; accord Eldridge v. Eli Lilly & Co., 485 N.E.2d 551, 553 (Ill. App. 1985) (without the learned intermediary rule, “the pharmacist would have to interject himself into the doctor-patient relationship and practice medicine without a license”); In re Depo-Provera (Depot Medroxyprogesterone Acetate) Products Liability Litigation, 2025 WL 2711592, at *3 (N.D. Fla. Sept. 22, 2025) (following Fakhouri) (applying Illinois law); In re Yasmin & Yaz (Drospirenone) Marketing, Sales Practices & Products Liability Litigation, 692 F. Supp.2d 1025, 1033 (S.D. Ill. 2010) (policy “reasons” supporting learned intermediary rule include avoiding “[i]nterference with the doctor-patient relationship”); In re Yasmin & Yaz (Drospirenone) Marketing, Sales Practices & Products Liability Litigation, 692 F. Supp.2d 1012, 1018 (S.D. Ill. 2010) (same); Stephens v. CVS Pharmacy, 2009 WL 1916402, at *3 (N.D. Ill. June 11, 2009) (following Fakhouri); Jones v. Irvin, 602 F. Supp. 399, 402 (S.D. Ill. 1985) (“Placing these duties to warn on the pharmacist would only serve to compel the pharmacist to second guess every prescription a doctor orders in an attempt to escape liability.”).

Indiana:  Ingram v. Hook’s Drugs, Inc., 476 N.E.2d 881 (Ind. App. 1985):

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. . . .  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.

Id. at 886-87 (footnote omitted).

Iowa: Madsen v. American Home Products Corp., 477 F. Supp.2d 1025, 1033 (E.D. Mo. 2007) (“states want to preserve the doctor-patient relationship which could be undermined if patients received warnings from drug manufacturers that differed from doctor’s warnings”) (applying Iowa law).

Kansas:  Nichols v. Central Merchandise, Inc., 817 P.2d 1131, 1133 (Kan. App. 1991) (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”).

Maine:  Tardy v. Eli Lilly & Co., 2004 WL 1925536, at *2 (Me. Super. Aug. 3, 2004) (“The injection of a third party . . . into the physician/patient relationship could undercut the effectiveness of the ongoing medical treatment by the physician. . . .  [T]he patient would be receiving information about the risks of medication . . . from someone unfamiliar with the patient’s medical condition, after those risks had already been weighed by a physician having specific knowledge of the patient’s medical needs.”).

Massachusetts:  Yout v. Biogen Idec, Inc., 2015 WL 13697200, at *4 (Mass. Super. Oct. 15, 2015) (“Requiring the manufacturer to provide warnings directly to the consumer would interfere with the doctor-patient relationship.”).

Michigan:  Mowery v. Crittenton Hospital, 400 N.W.2d 633, 637 (Mich. App. 1986) (“a duty to warn the user directly would cause undue interference with the relationship between doctor and patient”) (citations omitted); Nichols v. McNeilab, Inc., 850 F. Supp. 562, 570 (E.D. Mich. 1993) (“The rationale behind the [learned intermediary rule] has been stated as avoiding the confusion and unnecessary interference with the doctor/patient relationship which might result if drug manufacturers were required to warn patients directly of their drug’s possible side effects.”); Hickey v. Tennessee Gas Pipeline Co., 1992 WL 236915, at *3 (E.D. Pa. Sept. 9, 1992) (“A warning to the patient under these circumstances could potentially cause undue interference with the doctor-patient relationship, cause patient confusion, and result in a hampering of the healing process.”) (quoting and following Mowery) (applying Michigan law); Reaves v. Ortho Pharmaceutical Corp., 765 F. Supp. 1287, 1289 (E.D. Mich. 1991) (“[t]he learned intermediary doctrine protects the physician-patient relationship”).

Missouri:  Puricelli v. Genetech, Inc., 2011 WL 1576779, at *2 n.2 (E.D. Mo. April 26, 2011) (“states want to preserve the doctor-patient relationship which could be undermined if patients received warnings from drug manufacturers that differed from doctor’s warnings”) (citation and quotation marks omitted).

New Jersey:  Jones v. Synthes USA Sales, LLC, 2010 WL 3311840, at *4 n.3 (D.N.J. Aug. 19, 2010) (the learned intermediary rule has a rationale which . . . prevents the court from intruding upon the doctor-patient relationship”); Simineri v. LifeCell Corp., 2015 WL 3384588, at *8 (N.J. Super. Law Div. May 8, 2015) (“To require [defendant] to communicate directly with the patient would unnecessarily intrude on the doctor-patient relationship.).

New York:  In a pharmacy case, Abrams v. Bute, 27 N.Y.S.3d 58 (N.Y. App. Div. 2016), held:

Courts have been reluctant to impose a standard of care on pharmacists that would . . . require pharmacists to exercise their own professional judgment in a manner that could conflict with that of the prescribing physician. . . .  Accordingly, a rule that requires a pharmacist to independently evaluate the propriety of a physician’s prescription would not only place an undue burden on pharmacists, but would likely create antagonistic relations between pharmacists and physicians and interfere with the patient-physician relationship.

Id. at 66-67 (citations and quotation marks omitted).  Accord Brumaghim v. Eckel, 944 N.Y.S.2d 329, 332 (N.Y. App. Div. 2012)  (imposing “duties to warn on the pharmacist would only serve to compel the pharmacist to second guess every prescription a doctor orders in an attempt to escape liability”); Bee v. Novartis Pharmaceuticals Corp., 18 F. Supp.3d 268, 295 (E.D.N.Y. 2014) (quoting and following Hogan); Hogan v. Novartis Pharmaceuticals Corp., 2011 WL 1533467, at *10 (E.D.N.Y. April 24, 2011) (“Broadly speaking, 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.”).

Oklahoma:  Carista v. Valuck, 394 P.3d 253, 259 (Okla. App. 2016) (rejecting “broad expansion to the duties of pharmacists” that would “second-guess the judgment of a doctor in prescribing drugs” and “would result in pharmacists acting as a form of second medical opinion, and certainly could enmesh pharmacists in the practice of medicine.”  Rather pharmacist duties are “limited by the principles and exceptions to the learned intermediary doctrine”) (footnote omitted).

Pennsylvania:  Makripodis v. Merrell-Dow Pharmaceuticals, Inc., 523 A.2d 374, 378 (Pa. Super. 1987) (“A requirement that a pharmacist provide to the consumer the same warnings that the drug manufacturer must supply to prescribing physicians would intrude upon the doctor-patient relationship.”); Polt v. Sandoz, Inc., 462 F. Supp.3d 557, 570 & n.18 (E.D. Pa. 2020) (quoting and following Coyle; “the physician, not the manufacturer, decides whether to prescribe drugs and explains the risks to consumers”); Ramirez v. Richardson-Merrell, Inc., 628 F. Supp. 85, 88 (E.D. Pa. 1986) (“To impose a duty to warn on the pharmacist, however, would be to place the pharmacist between the physician who, having prescribed the drug presumably knows the patient’s present condition as well as his or her complete medical history, and the patient. Such interference in the patient-physician relationship can only do more harm than good.”).

Rhode Island: Franks v. Coopersurgical, Inc., 722 F. Supp.3d 63, 91 (D.R.I. 2024) (the learned intermediary rule “puts the onus on a patient’s physician to inform her of the risks associated with a particular medical device because the physician is in a better position to understand the risks, and inform the patient of those risks by virtue of their doctor-patient relationship”) (citation omitted).

South Carolina:  Brooks v. Medtronic, Inc., 750 F.2d 1227, 1232 (4th Cir. 1984) (“[T]otal disclosure by a manufacturer would not be in the patient’s best interest.  One in a serious medical condition faces unwanted, unsettling and potentially harmful risks if advice, almost inevitably involved and longwinded, from non-physicians, contrary to what the doctor of his choice has decided should be done, must be supplied to him during the already stressful period shortly before his trip to the operating room.”).

Tennessee:  Laws v. Johnson, 799 S.W.2d 249, 254 (Tenn. App. 1990) (quoting and following Brooks, see South Carolina); Dunkin v. Syntex Laboratories, Inc., 443 F. Supp. 121, 123 (W.D. Tenn. 1977) (“attempts to give detailed warnings to patients could mislead patients and might also tend to interfere with the physician/patient relationship”).

Texas:  Butler v. Juno Therapeutics, Inc., 541 F. Supp. 3d 774, 786 (S.D. Tex. 2021) (“Texas law does not tie the [learned intermediary rule’s] protection to the specific conduct of the physician.  Rather, the protection is triggered by the presence of a physician-patient relationship.”); McKay v. Novartis Pharmaceuticals Corp., 934 F. Supp.2d 898, 910 n.90 (W.D. Tex. 2013) (multiple warnings from different sources would “undermine the prescribing doctor’s physician-patient relationship”), aff’d, 751 F.3d 694 (5th Cir. 2014); Solomon v. Bristol-Myers Squibb Co., 916 F. Supp.2d 556, 563 (D.N.J. 2013) (“Recognizing the doctor-patient relationship, the [learned intermediary rule] excuses a drug manufacturer from warning each patient who receives the product when the manufacturer properly warns the prescribing physician of the product’s dangers.”) (citation and quotation marks omitted) (applying Texas law).

Vermont:  Baker v. University of Vermont, 2005 WL 6280644 (Vt. Super. May 4, 2005) (“[R]equiring 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.”) (citation and quotation marks omitted).

Washington:  Long v. Rite Aid Headquarters Corp., 2019 WL 1370442, at *3 (Wash. App. (March 25, 2019) (“The duty to warn about potential adverse side effects must be the sole obligation of the prescribing physician because the physician may often have valid reasons for deviating from the drug manufacturer’s recommendations based on a patient’s unique condition.”; “excessive warnings . . . could cause unfounded fear and mistrust of the physician’s judgment, jeopardizing the physician-patient relationship and hindering treatment”) (quotation marks and footnotes omitted).

West Virginia:  City of Charleston v. Joint Commission, 473 F. Supp. 3d 596, 625 (S.D.W. Va. 2020) (The learned intermediary rule reflects both “the concern that direct warnings to ultimate users would interfere with doctor/patient relationships” and “the corollary principle that physicians exercise their independent clinical judgment in patient evaluations”) (citation and quotation marks omitted); Ashworth v. Albers Medical, Inc., 395 F. Supp.2d 395, 407 (S.D.W. Va. 2005) (the learned intermediary rule “arises from the recognition of the primary role of the patient’s physician in diagnosing a particular condition or ailment and prescribing a course of treatment and from the reluctance to place a duty on a manufacturer that may interfere with the physician-patient relationship”).

Based on this survey of the law – including decisions from 29 different jurisdictions as recent as 2024 and 2025, and as old as 1971 −  it should be unmistakable that protection of the physician-patient relationship and prevention of that relationship being undermined by overly expansive warning duties concerning prescription medical products are at the core of the universally applicable learned intermediary rule.  This is not some tangential concern that only governs a small subset of learned intermediary cases.  No.  Preservation of the physician-patient relationship from disruption by third-party sources of generalized medical information, be they manufacturers, distributors, pharmacists, or whatever, is at the heart of the learned intermediary rule.

That’s why we are disturbed by the rationale of the recent decision in Himes v. Somatics, LLC, 549 P.3d 916, 926 (Cal. 2024) (discussed here).  Himes embraced a pernicious theory of warning causation that is fundamentally at odds with the learned intermediary rule’s purpose of protecting the physician-patient relationship from damage by product liability litigation.  Here’s why – it allows plaintiffs to get to the jury with otherwise hopeless causation evidence by testifying that had they known of some prescription-product-related risk they would have rejected their physician’s recommendation to use the product in question.  Forget possibly divergent warnings from different sources, we can think of nothing more corrosive of the physician-patient relationship than the prospect of liability turning on patient non-compliance with medical recommendations.

Here’s how things happened in Himes:  The plaintiff had previously been “prescribed at least nine different antipsychotics and antidepressants to treat depression, but her condition worsened,” and plaintiff “was hospitalized several times for severe depression or suicidal ideation.”  549 P.3d at 921.  As a last resort, one of her physicians treated plaintiff with electroshock therapy using the defendant’s device.  Id.  She was warned that the therapy “could cause short-term memory loss” but claimed that the defendant’s label did not disclose “permanent” brain damage and amnesia.  Id.  The doctor testified, however, “that he still would have recommended [the therapy] even if he had been informed of th[ose] risk[s].”  Id. at 922.  That additional information would not have changed a prescribing physician’s treatment is a well-established basis for severing causation as a matter of law in learned intermediary rule cases.

But Himes held that the plaintiff could overcome this testimony with evidence that “the [prescribing] physician would have communicated the stronger warning” to the plaintiff, and further that “an objectively prudent person in the patient’s position would have thereafter declined the treatment notwithstanding the physician’s continued recommendation of the treatment.”  Id. at 921 (emphasis added).

That formulation is totally at odds with all the above precedent establishing that preservation of the relationship of trust represented by the physician-patient relationship is a fundamental goal of the learned intermediary rule.  Even though there was significant California law favoring the preservation of the physician-patient relationship (see above), neither that precedent (be it from California or elsewhere), nor the relationship itself was mentioned in Himes.  Instead, Himes analogized to informed consent. “Implicit in our informed consent rule is the recognition that patients will sometimes opt out of the medical treatments their physicians recommend, as is their right.”  Id. at 926.  We agree with that statement as far as it goes, but we don’t think that a patient’s right to act contrary to medical advice should be weaponized into a cause of action – nor has any other court that we know of.

Moreover, the sort of evidence that Himes envisioned is not just plaintiffs with dollar signs in their eyes testifying that “if they had only known,” of course they would never have consented to the recommended drug/device/vaccine.  We’re not talking about Taxotere plaintiffs claiming that they, personally, would have refused to take a life-saving cancer drug because of hair loss or crying excessive tears.  See Id. at 932 (“If a subjective test were used, a plaintiff could simply offer self-serving testimony asserting that he or she would have declined the recommended treatment after being informed of the risks.”).

No, this formulation is more pernicious than a plaintiff relying on his or her own obviously biased testimony.  Himes demands purportedly “objective” testimony.  This test potentially requires rummaging through the entire physician-patient relationship in search of a basis for a jury to conclude that the physician’s judgment was so incorrect that an “objectively prudent patient” would have refused to comply:

[R]elevant factors that should be considered in determining whether an objectively prudent patient would have declined physician-recommended treatment include, but are not necessarily limited to, whether the physician weighed and assessed the risks and benefits of the treatment and, after discussing those risks and benefits with the patient, continued to recommend the treatment; whether the treatment was novel or was instead an established method for addressing the patient’s condition; the availability and utility of alternative treatments and the degree to which they have previously been tried in an effort to address the patient’s condition; the severity of the patient’s condition; and the likelihood that the treatment would have resulted in more than marginal benefits to the patient.

Id. at 931.

Thus, Himes has authorized plaintiffs – and eventually, juries, to second-guess essentially every aspect of medical decision-making – the quality of the doctor’s initial prescription decision; the quality of the discussion between the physician and the patient; whether the treatment was “novel” or “established”; alternative treatments; and the extent of both the medical risks and benefits.  Basically, under the guise of proving “causation,” Himes has imported into California prescription product liability litigation the entire range of proof normally seen in informed consent cases where the plaintiff sues his or her physician.  The plaintiff is thus encouraged to attack every aspect of the physician’s decision-making.  Such proof is necessarily destructive of the physician-patient relationship and thus directly at odds with one of the nationally accepted pillars of the learned intermediary rule.

We also point out that Himes is fundamentally different from another adverse learned intermediary rule decision, Blackburn v. Shire U.S., Inc., 380 So.3d 354 (Ala. 2022) (discussed here), that we have often criticized in the same breath for dumbing down learned intermediary rule-related causation requirements.  While Blackburn did indeed liberalize warning causation in Alabama, it did so in a way that did not require attacks on the functioning of the physician-patient relationship.  Rather, Blackburn was dependent on the physician’s own conduct, as testified to by the physician.  Blackburn involved instructions on how to monitor the development of adverse reactions.  Thus, a major question was “whether information provided by a prescription-drug manufacturer would have changed how a physician chose to monitor a patient.”  Id. at 368 (emphasis original).  The physician testified in Blackburn that if the defendant’s warnings had included more monitoring, “he ‘would have followed those protocols.’”  Id. at  357.  The plaintiff in Blackburn was not incentivized to attack the prescriber’s actions.  We think Blackburn was wrongheaded for other reasons – such as ignoring the undisputed fact that the plaintiff failed to keep subsequent medical appointments, and thus could not have been monitored at all.  Blackburn v. Shire U.S., Inc., 2020 WL 2840089, at *5 (N.D. Al. June 1, 2020).  But as bad as Blackburn was, at least it did not encourage patients to claim they would have disregarded medical device as a means to prove causation.