The Ninth Circuit has affirmed that the trial court did not err in granting summary judgment for defendant Merck under California’s learned intermediary doctrine in a failure to warn case. Latiolais v. Merck & Company, Inc., 2008 WL 5157705 (9th Cir. 2008).

Latiolais appealed the district court’s grant of summary judgment on her claim that Merck failed to adequately warn, as a result of inadequate testing, of claimed suicide risks associated with the cholesterol-lowering medication Zocor.

Under California’s learned intermediary doctrine, a prescription drug manufacturer’s duty to warn runs to the physician. A product defect claim based on insufficient warnings cannot survive summary judgment if stronger warnings would not have altered the prescribing physician’s conduct. See Motus v. Pfizer, Inc., 358 F.3d 659, 661 (9th Cir.2004).

Here, there was no genuine issue of material fact as to causation made out by the prescriber’s deposition testimony. It indicated that the drug inserts accompanying Zocor did not play a role in his decision to prescribe that medication. Furthermore, Dr. Oppenheim was not equivocal regarding whether he would have prescribed Zocor in light of a supposed warning of suicide risk associated with Zocor. Such a warning was deemed “hypothetical” by the court, and, in any event, could come into play only after one makes several assumptions on issues that include whether Merck was obligated to issue a suicide risk warning for Zocor, whether Dr. Oppenheim would have read or heeded such a warning, and what information Mr. Davis would have disclosed to Dr. Oppenheim with respect to his mental state. Such speculation did not create an issue of fact.