In the first federal preemption case of its kind to be ruled on at the appellate level, the U.S. Court of Appeals for the Eighth Circuit (ND, SD, MN, NE, IA, MO, AK) held that generic drug manufacturers may be liable for failure to warn. Mensing v. Wyeth, Inc., 2009 WL 4111209 (8th Cir. Nov. 27, 2009).

Mensing brought failure to warn and misrepresentation claims against both the name brand manufacturers of Reglan and generic manufacturers of its bioequivalent — metoclopramide. She took only the generic drug, took it for four years to treat her diabetic gastroparesis and developed tardive dyskinesia, a severe neurological movement disorder. The district court dismissed the claims against the generic manufacturers based on federal preemption and against the name brand manufacturers based upon the fact that Mensing had not taken their products. Relying upon Wyeth v. Levine, 129 S. Ct. 1187 (2009), in which the Supreme Court held that failure to warn claims against name brand manufacturers are not preempted, the Eighth Circuit in Mensing affirmed the judgment in favor of the name brand manufacturers but reversed as to the generic manufacturers.

The generic defendants argued that federal law, namely the Food, Drug and Cosmetic Act (the FDCA) and Hatch-Waxman Amendments thereto, preempt state law failure to warn claims. The Eighth Circuit began its analysis by citing Wyeth, and, based upon Wyeth, viewing "with a questioning mind" the argument that Congress "silently intended" to grant generic manufacturers "blanket immunity from state tort liability when they market inadequately labeled products."  Mensing at *3.

When a federal law does not expressly preempt state law claims, they may nevertheless be preempted if: (1) compliance with both federal and state law is impossible, or (2) the claims would "stand[ ] as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress." Mensing at *4, citing Crosby v. Nat'l Foreign Trade Counsel, 530 U.S. 363, 372-373 (2000). On the question of whether the generic defendants in Mensing could have fulfilled both a state law duty to warn and comply with the FDCA, the Eighth Circuit noted that the generic defendants could have proposed a label change, they could have suggested that the FDA send out a warning letter to health care professionals, or they could have simply stopped selling the product. Thus, the court concluded that they could have complied with both federal and state law and, if Mensing's injuries resulted from their failure to warn, the generic defendants may be held liable.

On the question of whether compliance with state law would obstruct the purposes and objectives of federal law, the generic defendants argued that proposing a label change would require expensive clinical studies, thwarting the goal of the Hatch-Waxman amendments to bring low cost generic drugs to market quickly. Noting that the scientific substantiation for label changes need not be acquired through a manufacturer's own clinical tests but can come from adverse drug experiences, which generic manufacturers are required to collect and report, the Eighth Circuit "decline[d] to assume that Congress intended to shield from tort liability the manufacturers of the majority of prescription drugs consumed in this country and leave injured parties like Mensing no legal remedy." Id. at *8.

Turning to Mensing's claims against the name brand manufacturers, the Eighth Circuit found that, under Minnesota law, Mensing had not shown that the name brand manufacturers owed her a duty of care necessary to trigger liability because she did not purchase or use their name brand products. Id. at *9. On this point, the Mensing decision is also in line with the Fourth Circuit in Foster v. American Home Products Corp., 29 F.3d 165 (4th Cir. 1994) and more recently the Southern District of West Virginia, Meade v. Parsley, 2009 WL 3806716 (S.D. W.Va. Nov. 13, 2009), and contrary to a California appellate court decision, Conte v. Wyeth, Inc., 168 Cal. App. 4th 89, 85 Cal. Rptr. 3d 299 (2009).