November 21, 2010

Darvon Removed From US Drug Market

Kentucky-based Xanodyne Pharmaceuticals has pulled its popular narcotic painkiller, Darvon, from the drug market because it may cause fatal heart rhythms, the US Food and Drug Administration (FDA) announced on Friday.

The FDA said it asked Xanodyne to stop selling Darvon and Darvocet after recent data confirmed that the active ingredient, propoxyphene, could cause serious and possibly fatal heart abnormalities.

The new decision leaves patients with even fewer safe options to manage pain, the FDA said. The agency said that 10 million patients took Darvon or a generic version last year.

"These new heart data significantly alter propoxyphene's risk-benefit profile. The drug's effectiveness in reducing pain is no longer enough to outweigh the drug's serious potential heart risks," Dr. John Jenkins of the FDA's Center for Drug Evaluation and Research said in a statement to Reuters.

Dr. Sidney Wolfe of the Public Citizen's Health Research Group said it was too little, too late. "Due to FDA negligence, at least 1,000 to 2,000 or more people in the United States have died from using propoxyphene since the time the U.K. ban was announced," he said in a statement.

An FDA advisory panel was deadlocked on whether to ban the drug in 2009. It was pulled from the market in June 2009 by the European Medicines Agency.

"The FDA's pitiful excuse that it needed to order a human study to find that 'the drug puts patients at risk of potentially serious or even fatal heart rhythm abnormalities' before deciding whether to ban propoxyphene only emphasizes how out-of-step the agency is with the rest of the world," Wolfe told Reuters.

The FDA, however, noted that many patients take the drug and that there are few other choices that equal the mild opioid. These include mostly over-the-counter pain relievers such as aspirin, ibuprofen and acetaminophen, as well as prescription codeine, oxycodone or hydrocodone.

The FDA said it was difficult to show that deaths from the use of Darvon were not the result of overdoses. But a comparison with similar drugs showed propoxyphene was much more dangerous.

"Over a five-year period, the number of drug-related deaths was approximately 16 deaths per 100,000 prescriptions for propoxyphene, 10 deaths per 100,000 prescriptions for tramadol and 8 deaths per 100,000 prescriptions for hydrocodone," the FDA said in a statement.

The FDA advised healthcare professionals to stop prescribing propoxyphene and said patients taking it should talk with their doctor about changing to another drug as soon as possible.

"Since 1978, the FDA has received two requests to remove propoxyphene from the market. Until now, the FDA had concluded that the benefits of propoxyphene for pain relief at recommended doses outweighed the safety risks," the FDA said.

Dr. Gerald Dal Pan of the FDA said Darvon does not cause permanent damage to the heart, and once patients stop using propoxyphene, "the risk will go away."


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