The Learned Intermediary Rule and Direct-to-Consumer Advertising

By Zachary Shapiro

In the field of pharmaceutical product-liability litigation, the Learned Intermediary Rule (LIR) is a defense doctrine for failure to warn claims, which has been adopted in 22 states, and applied in 48. The LIR means that if a pharmaceutical manufacturer that gives an adequate warning to a prescribing physician, the company has no corresponding duty to directly warn the patient.

This rule has been justified by the belief that the prescribing physicians is “in a superior position to impart the warning and can provide an independent medical decision as to whether use of the drug is appropriate for treatment of a particular patient.” Larkin v. Pfizer, Inc. 153 S.W.3d 758, 763-764 (Ky. 2004). Furthermore, historically, pharmaceutical manufacturers lacked effective means to communicate directly to patients. Courts did not want to extend liability when pharmaceutical companies were complying with FDA regulations regarding proper warnings to consumers. Finally, there was a belief that any direct warning would interfere with the doctor-patient relationship.  Continue reading