The Supreme Court appeared likely Monday to decide an amputee's lawsuit against a drug maker based on how much federal regulators knew about an anti-nausea drug's risks in the event of a botched injection.

Several justices indicated that if the U.S. Food and Drug Administration had clear information about the risks of Wyeth Pharmaceuticals' anti-nausea drug Phenergan, and approved its warning label anyway, then Wyeth probably would prevail in its court fight against Diana Levine of Vermont.

But there was considerable skepticism among the justices — and disagreement between the opposing lawyers — that the FDA had a clear picture of the disastrous consequences of improperly giving Phenergan by an intravenous method of injection known as IV push, the fastest way to bring relief to nauseated patients.

"How could the FDA have concluded that IV push was safe and effective," Justice Samuel Alito asked, given that Phenergan is not a lifesaving drug and gangrene can result from improper administration?

Justice Ruth Bader Ginsburg chimed in, "No matter what benefit there was, how could the benefit outweigh that substantial risk?"

Levine, a guitar- and piano-playing musician from Vermont, was in the courtroom for Monday's arguments in Wyeth's appeal of a $6.7 million verdict she won from a state jury.

The jury agreed with Levine's claim that Wyeth failed to provide a strong and clear warning about the risks of IV push, which include that gangrene is likely if the injection accidentally hits an artery. That is precisely what happened to Levine.

The company appealed and, backed by the Bush administration, argued that once a drug's warning label gets FDA approval, consumers cannot pursue state law claims that they were harmed.