Warner-Lambert Co. v. Kent, 552 U.S. 440 (2008)

In Warner-Lambert Co. v. Kent, the underlying dispute arose from claims made by consumers who alleged that the pharmaceutical company Warner-Lambert misrepresented the safety and efficacy of its product, Listerine. The plaintiffs, including Kimberly Kent, contended that the company engaged in deceptive marketing practices, leading them to purchase the mouthwash under false pretenses. The case centered on whether these claims were preempted by federal law, specifically the Federal Food, Drug, and Cosmetic Act, which governs the regulation of drug labeling and advertising. The procedural history of the case began in the United States District Court for the Southern District of New York, where the plaintiffs filed a lawsuit against Warner-Lambert. The district court dismissed the case, ruling that the claims were preempted by federal law. The plaintiffs appealed this decision to the United States Court of Appeals for the Second Circuit, which reversed the district court's ruling, allowing the claims to proceed. Warner-Lambert then sought a writ of certiorari from the Supreme Court, which ultimately affirmed the Second Circuit's judgment by an equally divided Court, with the Chief Justice recusing himself from the case. This case is significant in the context of the ongoing debate over the balance between state consumer protection laws and federal regulatory authority. The outcome highlighted the complexities involved in determining the extent to which federal law can preempt state law claims, particularly in the pharmaceutical industry, where safety and efficacy claims are heavily regulated. The ruling also underscored the importance of consumer rights in the face of potentially misleading marketing practices by large corporations.

Whether a state law claim that is based on the alleged failure to adequately warn consumers about the risks associated with a pharmaceutical product is preempted by federal law.

The judgment is affirmed by an equally divided Court.