There are a lot of things we like about the learned intermediary rule. We’ve discussed many of them before. One aspect of the rule that we’ve touched on, but haven’t really explored in depth is the effect of the rule on causation in duty to warn claims.
Concerning causation, the first thing anybody has to understand about failure to warn claims is that there’s two types of causation: The first is whether the drug (or any product, for that matter) caused the plaintiff to suffer the injury that s/he claims. That’s often called “cause-in-fact,” see, e.g., Eck v. Parke, Davis & Co., 256 F.3d 1013, 1017 (10th Cir. 2001), but since all causation in some sense “in fact” caused the injury, we prefer the term “medical causation.” This type of causation poses the question did the drug cause the adverse reaction or other harm that the plaintiff suffered?
This type of causation is the stuff of expert reports, epidemiology and Daubert motions. It’s not the stuff of this post.
The second prong is what courts sometimes call “proximate cause,” e.g., Eck, supra, but we think that’s an even more confusing moniker than cause in fact. We call it “warning causation,” or sometimes “defect causation.” When, as in most drug and medical device cases, the claimed “defect” is a warning that is allegedly inadequate in some way, the defect – the problem with the warning – must also be the cause of harm.
Warning causation sometimes becomes important in non-drug cases where, for instance, a plaintiff admits to throwing away the box the product (say, an air rifle, to use a well-known case) came in without reading any of the warnings on it. It’s hard to say in that case that a better warning could have made a difference when no warnings at all were read, much less followed. In those cases, plaintiffs usually resort to some sort of “you should have attached the warning physically to the product” claim.
In drug and medical device cases, the FDA says use a package insert. It’s not really practical to attach a warning physically to something that’s swallowed or implanted in the body anyway.
The problem with lots of warning claims that involve products like air rifles is that it’s not very often that a plaintiff is going to admit to something like throwing away the box without looking at it. In 99% of the cases, any decently prepared plaintiff (or other witness allied with the plaintiff) is going to testify that if the warning had only said “this can put your eye out” instead of just “never point at anyone” s/he wouldn’t have done whatever stupid thing s/he did that led to the injury.
The defendant, of course, might think that the plaintiff is lying through his or her teeth – but practically the first thing lawyers are taught on day one of law school is that only juries determine “credibility.” The plaintiff’s own testimony, no matter how transparently self-serving and refuted by every other fact in the case, is sufficient to create the dreaded “issue of fact.” An issue of fact (assuming it’s “material”) means the case is going to the jury. Even if the jury reacts exactly the way the defendant thinks it should, it’s only going to get that opportunity after the defendant has spent a whole lot of money trying the case.
That’s a simple fact of litigation life. It’s why a lot of perfectly winnable cases settle for what defendants call “nuisance value.”
The learned intermediary rule changes all this.
Under the learned intermediary rule, the warning that the defendant drug or device manufacturer is duty bound to give must be directed to the prescribing (usually, sometimes treating) doctor and not the plaintiff patient.
That’s critically important.
The doctor: (1) does not stand to get money if s/he testifies a particular way, (2) is a professional who not only has a lot of training and knowledge, but is under an professional obligation to keep that knowledge current, and (3) may well not like lawyers – especially personal injury lawyers (who also bring malpractice suits).
All this means is that there’s a far better chance of getting a doctor to say something like, “I already knew that from the medical literature I routinely read,” or “I relied on my training, not the warnings,” or “I wouldn’t have done anything different even if I’d had a different warning,” or “I would never allow myself to be influenced by anything a drug salesman told me.”
Any one of those statements would mean that the claimed “defect” – the inadequacy in the warning – didn’t cause the injury because even an adequate warning wouldn’t have prevented the plaintiff from being prescribed the drug/device and thus being injured.
And any one of these statements thus means (or should mean), that there’s no issue of fact. No issue of fact translates (or should) into summary judgment for the defendant – no matter how many times the plaintiff claims that, if a “better” warning had somehow gotten through to the plaintiff him or herself, the plaintiff would have refused to use the product (Even against doctor’s orders? Yeah, right. But that’s the dreaded credibility dispute again).
More than anything else, that’s why we think, on a day to day basis, plaintiffs don’t like having to live with the learned intermediary rule. It puts the place where the causation rubber meets the road in a location beyond anything that they can easily control – in the testimony of independent third parties instead of in the testimony of their own clients.
That’s why plaintiffs try so hard to limit informal defense access to prescribing physicians in drug cases – while all the while seeking to maximize their own informal access (so they can have conversations to the effect that, “if you say that, you’re admitting malpractice, and we’ll sue you,” among other things).
And know what? We can’t blame the other side for feeling that way. We win a lot of cases on causation due to the prescribing physician’s testimony – and we’ve been winning a lot lately. Just in the last four months:

• In Porter v. Eli Lilly & Co., 2008 WL 544739 (N.D. Ga. Feb. 25, 2008), aff’d, 2008 WL 4138115 (11th Cir. Sep. 9, 2008) (unpublished), a suicide case, the doctor said he “would have done the exact same thing” because the plaintiff had exhibited no signs of being suicidal. It wasn’t his practice to introduce the subject of suicide to depressed patients who weren’t already suicidal. Thus no stronger suicide warning would have made a difference, any “heeding presumption” was preempted, and the defendant was entitled to summary judgment. Id. at *12-13.
• In Longs v. Wyeth, 536 F. Supp.2d 843, 2008 WL 542387 (N.D. Ohio Feb. 28, 2008), a fen-phen case, the doctor testified that he had received “Dear Doctor” letters from the defendant and was also aware of the risk at issue from other medical sources. As a result he made it a practice to discuss the risk with patients before prescribing the drug. Whether or not the prescriber in fact discussed the risk with plaintiff was not a material factual dispute in light of the physician’s own undisputed knowledge. Thus, the defendant was entitled to summary judgment. Id. at *11.
• In Allgood v. Glaxosmithkline Plc, 2008 WL 483574 (E.D. La. Feb.20, 2008), another suicide case, the doctor testified that, even knowing everything he now knows today, he would have made the same prescription decision for the plaintiff; he would not have given the plaintiff any additional warning; and he prescribes from “experience” and “the hell with” what the manufacturer says. There was plainly no warning causation and the defendant was entitled to summary judgment. Id. at *6.
• In Ebel v. Eli Lilly & Co., 536 F. Supp.2d 767, 2008 WL 482722 (S.D. Tex. Jan. 29, 2008), yet another suicide case, the doctor testified that “he knew of the very risks” that the plaintiff complained of. Prescription of a product with full knowledge of the alleged risk was sufficient to break any causal connection between alleged omissions in the warnings and injury, entitling the defendant to summary judgment. Id. at *10-11.
• In Vanderwerf v. SmithKlineBeecham Corp., 529 F. Supp.2d 1294 (D. Kans. 2008), still another suicide case (we had good reason for our recent remark that plaintiffs have a lot of non-preemption problems with suicidality cases), two doctors testified that “even with the information which they have today. . .they would have prescribed” the drug to the plaintiff. This testimony was sufficient to rebut any “heeding presumption,” to defeat warning causation, and to entitle the defendant to summary judgment. Id. at 1310-12.
• In Ethicon Endo-Surgery, Inc. v. Meyer, 249 S.W.3d 513, 2007 WL 4462713 (Tex. App. Dec. 20, 2007), involving a surgical stapler, the doctor, an experienced surgeon, testified that “he did not need” the defendant manufacturer to tell him about certain surgical risks, and that had he received some sort of “safety alert,” it would have “g[i]ve[n] him no more knowledge than he already had,” and “would not affect his approach to a surgery.” The surgeon’s “independent knowledge” of the risk defeated warning causation as a matter of law and entitled the defendant to a take nothing judgment notwithstanding a contrary jury verdict. Id. at *5-6.
• In Simon v. Wyeth Pharmaceuticals, Inc., 2007 WL 4673679 (Pa. C.P. Phila. Co. Dec. 26, 2007), a hormone replacement case, the evidence failed to show that any of the doctors would have changed their prescription habits and not prescribed the drug to plaintiff had they received what the plaintiff claimed was an adequate warning. Rather, these doctors still prescribed the drugs and were “adamant” about them. This testimony defeated warning causation as a matter of law (Pennsylvania does not recognize any heeding presumption) and the defendant was entitled to judgment n.o.v. Id. at *__ (there are unfortunately no page cites available in Westlaw “trial orders” – complain to them, not us).
• In Nelson v. Wyeth, 2007 WL 4261046 (Pa. C.P. Phila. Co. Dec. 5, 2007); another hormone replacement case, the doctor testified that she “did not read nor rely upon any of [defendant’s] warnings as contained in the label.” Rather the doctor relied “upon literature, textbooks, conferences and journal articles.” This testimony defeated warning causation as a matter of law, and the defendant was entitled to judgment n.o.v. Id. at *__ (again, there are unfortunately no page cites available in Westlaw “trial orders”).

That’s eight cases in four months in which negative testimony from prescribing physicians has defeated warning causation as a matter of law – five summary judgments (in federal court) and three judgment n.o.v.’s (in state court). That says something in and of itself, but that’s for another post on another day.
Long live the learned intermediary rule.
We like winning, which is why we like the learned intermediary rule. Sure, it’s winning only one case at a time, as opposed to wiping out lots of cases with one fell preemption or Daubert fell swoop. But winning sure beats losing. Thus, good warning causation testimony is the defense objective number one in any prescriber’s deposition.
Oh yeah, one other, sort of related thing.
There’s still the occasional “I threw away the box” case where the plaintiff cuts his or her own throat without waiting for the prescriber to do it. One of those happened recently (during the same four months) in Rush v. Wyeth, 514 F.3d 825 (8th Cir. 2008). In Rush (another hormone replacement case) the plaintiff “admi[tted] that she never read the warnings [the defendant] included with each prescription.” Id. at 829. That means Rush was a (relatively rare) direct patient warning case. We can’t tell from the opinion whether the defendant provided the patient warnings voluntarily, or due to applicable FDA regulation (the agency requires direct patient warnings in some situations), or for some other reason – but in any event the plaintiff’s own conduct handed the defendant the same sort of warning causation argument more commonly based upon prescriber testimony in learned intermediary cases.
Summary judgment?
Nope – a defense verdict. That the case went to verdict in federal court sort of underscores (it’s a bit of a reach, we admit) the basic point made above – that it’s the testimony of the learned intermediary doctor which not only packs the summary judgment punch, but also can’t be mucked up by other testimony by the plaintiff. Somewhere in Rush, the plaintiff must have said things (we don’t claim to know what) that detracted enough from her admission to create some colorable fact issue. Of course, how colorable it had to be depends, to some extent, on the judge as well as the facts. Anyway, Rush ended up with a jury question, and the fight then was about instructing the jury that the defendant had the right to expect the plaintiff to read what was put in front of her. Id. at 829.
So even if we get “I threw away the box” type admissions from the plaintiff, in a learned intermediary rule case, it’s still not as good as testimony from the prescribing doctor that – in any of the ways illustrated in the eight cases we’ve just described – that severs the causal chain at the prescriber level.