Once a heavily marketed and almost fashionable painkiller, Darvon is coming off the market.
The Food and Drug Administration said Xanodyne Pharmaceuticals, the current maker of the brand-name pills Darvon and Darvocet (a combination with acetaminophen), has agreed to stop selling them. The agency also asked makers of generics (the active ingredient is propoxyphene) to follow suit.
How come? The agency says it pushed to remove the medicine, prescribed since the late 1950s, from the market after new data showed it "puts patients at risk of potentially serious or even fatal heart rhythm abnormalities." Overall, the drug's risks to patients outweigh its benefits, FDA said.
Early last year a panel of outside experts voted to recommend that propoxyphene, a mild opioid, be withdrawn. Overdoses and lingering questions about the drug's effectiveness in relieving pain were some of the issues, as MedPage Today reported at the time.
In July 2009, the FDA decided to leave propoxyphene on the market but required the companies that sold it to beef up warnings about overdose hazards. Xanodyne also had to study how the drug affects heart rhythms, and the results were shared with FDA recently. "With the new study results, for the first time we now have data showing that the standard therapeutic dose of propoxyphene can be harmful to the heart," the FDA's Dr. Gerald Dal Pan said in a statement.
Darvon's ability to fight pain has long been questioned. Back in 1972, a study published in the New England Journal of Medicine compared marketed pain relievers and found aspirin to be the best. Darvon was no better than a sugar pill.
At the time, the authors noted pointedly that propoxyphene had a "dubious record" in controlled clinical tests. Their own work, they said, represented the eighth published study that showed the drug wasn't better than a placebo.
Public Citizen's Health Research Group twice petitioned the FDA to withdraw propoxyphene drugs. In a statement today, the consumer group faulted the agency for taking so long to act, saying the delay since the U.K. decided to ban the drugs in 2005 resulted in the death of at least 1,000 Americans.