In one of the most eagerly awaited decisions of this Supreme Court session, the justices today ruled that drug companies are not shielded from personal injury claims even if the feds approved their products and packaging. The 6-3 decision is a victory for Diana Levine, a Vermont musician, now in her 60s, who sued drug giant Wyeth after she had to have her arm amputated because of a botched injection of the anti-nausea med Phenergan.

The ruling has wide-reaching implications for product liability and personal injury lawsuits, including those pending against Merck & Co. charging that its anti-inflammatory drug Vioxx dramatically increased heart attack and stroke risk.

"Federal law does not pre-empt Levine's claim," the justices wrote, "that Phenergan's label did not contain an adequate warning about the IV-push method of administration."

If you want to learn more about this case, check out our Ask the Experts interview with Sheila Scheuerman, a professor at the Charleston School of Law and an expert in product liability.

To sum up, Levine, a guitarist, suffered from migraines and often received an injection at a nearby clinic of Phenergan in her backside to treat related nausea symptoms. But on one tragic visit in 2000, instead of giving her a shot in the butt, the physician's assistant attempted to inject the drug directly into a vein in her arm using an alternative approved method called intravenous push.

The worker accidentally injected the drug into Levine's artery instead of a vein, which has the potential to cause a spasm in the artery, reducing the blood supply and sometimes leading to gangrene.  Indeed, the right-handed musician rapidly developed an infection in her right hand and forearm, and doctors were forced to amputate the blackened limb in two stages.

Although the packaging was approved by the Food and Drug Administration and described the risks of Phenergan, Levine's lawyers argued that the warning against IV-push should have been stronger.  A Vermont jury awarded Levine $6.7 million in damages, and the Vermont Supreme Court upheld the decision in 2006. But Wyeth appealed to the U.S. Supreme Court, which has now weighed in, putting the matter to rest.

The three justices who ruled against Levine were John Roberts, Antonin Scalia, and Samuel Alito, Jr., who penned the dissenting opinion.  "[I]t is odd (to say the least) that a jury in Vermont can now order for Phenergan what the FDA has chosen not to order for mustard gas," Alito wrote -- referring to the highly toxic but powerful chemical that, despite the significant risk, can be administered via IV push as an anticancer drug.

Seal of the US Supreme Court by the Department of Justice, via Wikimedia