Current Applications & Limitations on the Learned Intermediary Rule

What The Rule Is And How It Applies

To avoid liability, a manufacturer of a product has a duty to exercise reasonable care in giving adequate warnings to consumers of potential dangers from the use of its product. See Magee v. Wyeth Laboratories, Inc., 214 Cal.App.2d 340, 350, 29 Cal.Rptr. 322 (1963). In general, this duty to warn is owed to the consumer directly. However, a manufacturer of prescription drugs may fulfill the duty by providing adequate warnings to a physician who is prescribing the manufacturer's drugs to a patient. The prescribing physician is an "informed" or "learned" intermediary between the manufacturer and the patient. Love v. Wolf, 226 Cal.App.2d 378, 395, 38 Cal.Rptr. 183, 192 (1964); Hill v. Searle Laboratories, 884 F.2d 1064, 1070 (8th Cir. 1989).

The learned intermediary rule is a common law exception to liability. It applies when a pharmaceutical company informs prescribing physicians of any known or suspected risks associated with its product's use. Reyes v. Wyeth Laboratories, 498 F.2d 1264, 1276 (5th Cir. 1974), cert. denied, 419 U.S. 1096 (1974). Thus, "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." Love v. Wolf, supra, 38 Cal.Rptr. at 193. If the manufacturer meets this requirement, it cannot be held liable under a theory that it breached a duty to warn which it owed to the consumer. Swayze v. McNeil Laboratories, Inc., 807 F.2d 464, 469-70 (5th Cir. 1987).

In Desmarais v. Dow Corning Corp., 712 F.Supp.13,17 (D.Conn. 1989), a breast implant case, the district court described both the rule and the scope of its acceptance by the judiciary as follows:

This doctrine states 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 risks and benefits of a particular course of treatment. The learned intermediary doctrine has been adopted in most jurisdictions, including Connecticut.

Indeed, it is by virtue of the licensed physician's education, training, and experience that he or she is in the best position to make an individualized medical judgment as to which specific palliative to prescribe for a particular patient. See Mazur v. Merck & Co., 964 F.2d 1348, 1355-59 (3d Cir.1992); Windham v. Wyeth Laboratories, Inc., 786 F.Supp. 607, 611 (S.D.Miss. 1992).

In Mazur v. Merck, the court of appeals held that the nurse who supervised the administering of a vaccine at a school did not qualify as a learned intermediary because she had not undergone "the rigorous medical training necessary to become a licensed physician" and therefore was not capable of making the individualized medical judgment required under the rule. 964 F.2d at 1357-58. However, the Third Circuit did note that courts in other jurisdictions under limited circumstances have found a nurse to be a learned intermediary. Id. at 1356, 1360 n.18.

In part, the rationale behind an exception which allows a manufacturer to issue its warning to the physician instead of to the consumer is that "[a]s a medical expert, the prescribing physician can take into account the propensities of the drug, as well as the susceptibilities of his patient." Reyes v. Wyeth, supra, 498 F.2d at 1276. In observing that it is the physician's task to weigh the benefits of any drug against its potential dangers, the Reyes court stated (id.):

The choice he makes is an informed one, an individualized medical judgment bottomed on a knowledge of both patient and palliative. Pharmaceutical companies then, who must warn ultimate purchasers of dangers inherent in patent drugs sold over the counter, in selling prescription drugs are required to warn only the prescribing physician, who acts as a "learned intermediary" between manufacturer and consumer.

One court has stated the following three reasons for the rule:

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.

It would be virtually impossible for a manufacturer to comply with the duty of direct warning, as there is no sure way to reach the patient.

Carmichael v. Reitz, 17 Cal.App.3d 958, 989, 95 Cal.Rptr. 381, 400 (1971), quoting Rheingold, "Products Liability - The Ethical Drug Manufacturer's Liability," 18 Rutgers L.Rev. 947, 987 (1964). See Hill v. Searle Laboratories, supra, 884 F.2d at 1070.

The manufacturer's duty to inform learned intermediaries of the potential risks associated with the use of its prescription products...