Johnson & Johnson must pay $8 billion in punitive damages to a man who previously won $680,000 over his claims that it failed to warn that young men using its antipsychotic drug Risperdal could grow breasts, a Philadelphia jury said on Tuesday.

The Philadelphia Court of Common Pleas jury's verdict in favor of Nicholas Murray came in the first case in which a Pennsylvania jury had been able to consider awarding punitive damages in one of thousands of Risperdal cases pending in the state.

J&J and a lawyer for Murray did not immediately comment on the verdict.

The extremely large punitive damages award is likely to be reduced on the grounds that it violates due process.

In a 2003 case, the U.S. Supreme Court threw out a $145 million punitive damage award and held that, "few awards exceeding a single-digit ratio between punitive and compensatory damages, to a significant degree, will satisfy due process."

Murray, like other male plaintiffs in the mass tort litigation over Risperdal, alleges that he developed breasts after being prescribed the medicine, which the U.S. Food and Drug Administration approved in the 1990s only for treating schizophrenia in adults, when he was a minor.

Plaintiffs claim that J&J failed to warn of the risk of gynecomastia, the development of enlarged breasts in males, associated with Risperdal, which they say the company marketed for unapproved uses with children.