The company that makes the highly popular narcotic painkiller Darvon has pulled the drug from the market because it can cause fatal heart rhythms, the U.S. Food and Drug Administration said on Friday.
The FDA said it asked Kentucky-based Xanodyne Pharmaceuticals Inc. to stop selling Darvon and Darvocet after new data confirmed fears that the active ingredient, propoxyphene, could cause serious or even fatal heart rhythm abnormalities.
The decision means patients will have even fewer safe options to manage pain, the FDA said. The agency says 10 million patients took Darvon or a generic version in 2009 and 18 million prescriptions were dispensed.
"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.
Dr. Sidney Wolfe of the Public Citizen's Health Research Group said it was too little, too late, noting that Britain banned the drug six years ago.
"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," Wolfe said in a statement.
An FDA advisory committee split on whether to ban the drug in 2009. The European Medicines Agency pulled it from the market in June 2009.
"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 said.
Few Alternatives
But the FDA noted that many people take the drug and that there are few choices equivalent to the mild opioid. These include codeine, oxycodone, or hydrocodone as well as over-the-counter pain relievers such as aspirin, ibuprofen, and acetaminophen.
Aspirin and ibuprofen can cause fatal bleeding and codeine can cause severe constipation.
The FDA said it was difficult to show that deaths associated with Darvon use were not, in fact, overdoses. But a comparison with similar drugs showed propoxyphene was 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 eight deaths per 100,000 prescriptions for hydrocodone," the FDA said in a statement.
The FDA said it was advising healthcare professionals to stop prescribing propoxyphene and said patients taking it should speak to a doctor about switching 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.
The FDA's Dr. Gerald Dal Pan said Darvon does not cause permanent damage to the heart. "Once patients stop taking propoxyphene, the risk will go away," he said.
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