There’s a reason why prescribing physicians and implanting surgeons are called “learned” intermediaries. The law presumes that licensed doctors know what they are doing. That means that prescribers can make risk/benefit analyses to determine what prescription drugs or medical devices their patients need. As part of that process, such physicians necessarily also evaluate what risks they should tell – and not tell − their patients.
One consequence of a physician’s presumed medical competence is that a learned intermediary is within his/her rights to disregard a manufacturer’s warning altogether, to decide that a particular risk was not severe enough to make a difference, or to conclude that such a risk did not exist or was not material in the context of a particular patient’s medical needs. In all of these situations, the prescriber’s independent evaluation of what risks to credit, which to ignore, and which to omit in counseling patients breaks the causal chain of , entitling a manufacturer defendant to judgment on a warning claim concerning such risks. This scenario was the “third hypothetical” in our “Learned Intermediary Rule 201” post back in 2008.