In Wyeth v. Levine (2009), the Supreme Court held that the FDA's approval of the labeling for a brand-name prescription drug generally does not preempt a personal-injury state-law tort claim premised on the manufacturer's failure to warn about the drug. But, later, in PLIVA v. Mensing (2011), the Supreme Court held that state-law failure-to-warn claims are preempted by the FDA's labeling approval when the drug is a generic drug.
Why the difference? Well, mainly, according to the Supreme Court, the difference was that brand-name manufacturers can, by FDA regulation, unilaterally amend their labels to meet the safety demands of state law, but generic drug companies cannot. Rather, the Supreme Court said, generic labels must, in all cases, simply ape the labels of their brand-name counterparts (absent FDA pre-approval).
So, to help ensure that potential users of generic drugs get up-to-date safety information about generic drugs, in September 2011, Public Citizen filed a petition asking the FDA to amend its labeling rules to authorize generic drug manufacturers to make safety-related label changes without FDA pre-approval.