## Facts

- Patients ingested generic metoclopramide, the generic equivalent of brand-name Reglan, for several years and developed tardive dyskinesia.
- The drug’s labeling had been strengthened over time in response to evidence that long-term use can cause tardive dyskinesia.
- The patients sued generic manufacturers under state tort law, alleging failure to provide adequate warning labels about the risks of long-term use.
- The alleged state-law duty, as pleaded, required manufacturers who knew or should have known of dangers to provide stronger warnings than those on the labels used.
- Federal law required generic drug labels to be the same as the corresponding brand-name drug labels.

## Issues

1. Whether federal law governing generic-drug labeling preempts state-law failure-to-warn claims that would require a generic manufacturer to provide stronger warnings than the brand-name label.
2. Whether it is “impossible” for a generic manufacturer to comply with both a state-law duty to strengthen warnings and a federal duty to maintain label “sameness.”

## Decision

- The Supreme Court reversed the Fifth and Eighth Circuits and held the state-law failure-to-warn claims preempted.
- Because federal law prohibited generic manufacturers from independently changing their labels, they could not comply with a state-law duty requiring stronger warnings while also complying with federal “sameness” requirements.
- The Court rejected the argument that preemption is avoided because manufacturers could have asked the FDA to approve a label change; needing discretionary federal action and permission did not constitute independent ability to comply with state duties.
- The Court acknowledged policy concerns about differing liability exposure for brand-name and generic manufacturers, stating that any change was for Congress and the FDA.

## Legal Principles

- Impossibility preemption applies when a private party cannot comply with both state and federal requirements; in that event, state law is displaced.
- Generic manufacturers must maintain labeling that matches the reference listed (brand-name) drug, and federal law bars unilateral label strengthening that would break “sameness.”
- A state failure-to-warn duty that effectively requires a generic manufacturer to adopt a stronger warning than the brand-name label directly conflicts with federal generic-labeling requirements.
- The theoretical ability to petition or request agency action does not defeat impossibility preemption when compliance with state law would still depend on discretionary federal approval rather than the actor’s independent capacity.

## Conclusion

The Court held that federal generic-drug labeling requirements preempt state failure-to-warn claims where the claims would require generic manufacturers to strengthen warnings that federal law forbids them to change unilaterally, making simultaneous compliance with state and federal duties impossible.


PLIVA, Inc. v. Mensing, 564 U.S. 604 (2011)