What is the liability of a drug manufacturer for failing to warn of side effects associated with a prescription drug?

There are three theories of recovery which may be available to a plaintiff in an action against a prescription drug manufacturer if the manufacturer fails to warn of side effects association with a prescription drug: negligence, strict liability in tort, and breach of implied warranty. In any of the theories relied upon, the liability of a drug manufacturer in an action for a failure to warn of side effects associated with a prescription drug requires the plaintiff to allege (and later in the litigation, to prove) that: (1) the manufacturer had a duty to warn medical professionals or, in some limited cases, the consumer, regarding the known side effects of the drug; (2) the standard of care the manufacturer was required to use in fulfilling its duty to warn; (3) breach of the manufacturer's duty to warn by providing an inadequate warning; (4) injury suffered by the plaintiff is attributable to the manufacturer's failure to provide an adequate warning; and (5) the manufacturer's failure to warn was the proximate cause of the plaintiff's injury. See generally Carlin v. Super. Ct., 13 Cal. 4th 1104 (1996)).