When a patient in the United States fills a prescription, the likelihood that a generic drug will be dispensed is overwhelming—and increasing. Generic drugs account for more than 80% of prescriptions, but only 20% of total drug spending, because of their lower cost. The move to generics is estimated to have saved more than a trillion dollars in the last decade.1
Although generic drugs are bioequivalent to their brand-name counterparts, important legal distinctions between the 2 categories have resulted from 3 Supreme Court decisions. The first, Wyeth v Levine, arose after a woman developed gangrene in her forearm caused by intra-arterial injection of Wyeth’s antiemetic Phenergan (promethazine); the patient was awarded $6.7 million in damages based on her claim that the drug’s label did not sufficiently warn about its risks. In 2009, the Court upheld the award, noting that brand-name manufacturers are primarily responsible for providing accurate safety warnings for the drugs they produce.2 The decision makes sense because premarket testing does not reveal the full range of a drug’s adverse effects, postmarket surveillance by the US Food and Drug Administration (FDA) is insufficient, and state tort liability incentivizes manufacturers to continue monitoring the safety of their products.