According to FDA regulations, generic manufacturers must use the exact same warnings in their products as the makers of the brand name versions of the drugs. For this reason, the US Supreme Court has decided that claims against generic drug manufacturers for inadequate warnings are preempted.
However, back in February I reported that the FDA was considering a
regulatory change that would allow generic manufacturers to change the warnings on their products in
appropriate circumstances - perhaps in part because, at least according to one study, that was the practice already. See here.
The FDA has, in fact, now made its proposal official. Last Wednesday, the FDA proposed a new rule, which would allow generic drug manufacturers to update their labels with new warnings, even when the brand name is no longer on the market. Pharmalot and AboutLawsuits have more on the story here and here.