Five years after the Food and Drug Administration (FDA) first approved metoclopramide, a drug commonly used to treat digestive tract problems, under the brand name Reglan, generic manufacturers such as petitioners also began producing the drug. Because of accumulating evidence that long-term metoclopramide use can cause tardive dyskinesia, a severe neurological disorder, warning labels for the drug have been strengthened and clarified several times, most recently in 2009.

Respondents were prescribed Reglan in 2001 and 2002, but both received the generic drug from their pharmacists. After taking the drug as prescribed for several years, both developed tardive dyskinesia. In separate state-court tort actions, they sued petitioners, the generic drug manufacturers that produced the metoclopramide they took (Manufacturers). Each respondent alleged, inter alia, that long-term metoclopramide use caused her disorder and that the Manufacturers were liable under state tort law for failing to provide adequate warning labels. In both suits, the Manufacturers urged that federal statutes and FDA regulations pre-empted the state tort claims by requiring the same safety and efficacy labeling for generic metoclopramide as was mandated at the time for Reglan. The Fifth and Eighth Circuits rejected these arguments, holding that respondents’ claims were not pre-empted.