Since it was first approved back in 1957, more than 10 million people have received prescriptions for propoxyphene, a pain pill manufactured by Xanodyne Pharmaceuticals, Inc., and sold under the names "Darvon" and "Darvocet."
In November, after years of complaints and warnings -- backed by overwhelming evidence that the drug is linked to potentially deadly heart rhythm abnormalities -- the FDA finally asked the drug company to pull the product off the market. The FDA has also informed the generic manufacturers of propoxyphene-containing products of Xanodyne's decision, and requested that they voluntarily remove their products as well.
The wording of the FDA announcement left no doubt as to the alliance between the government agency and the drug industry: "The FDA is pleased by Xanodyne's decision to voluntarily remove its products from the U.S. market," said John Jenkins, MD, director of the Office of New Drugs in the FDA's Center for Drug Evaluation and Research (CDER). "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."
In fact, the drug was banned in Britain in 2005 and in the European Union in 2009. An FDA committee voted 14-12 for banning the drug in January of 2009 but the FDA let nearly two years pass before taking "asking" the drug maker to voluntarily stop selling the dangerous pill.
Research has shown that -- even at recommended doses -- the drug can significantly increase the risk of serious abnormal heart rhythms, especially in elderly patients and those with kidney problems. Yet, the FDA claims that their action was the result of a "new safety study" required of the manufacturer. "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," said Gerald Dal Pan, MD, MHS., director of the Office of Surveillance and Epidemiology, CDER.
The claim that this is the first evidence that the drug is dangerous "rings dangerously hollow," said Dr. Sidney Wolfe, director of Public Citizen's Health Research Group. In 1978, the consumer advocacy group Public Citizen petitioned the FDA to have the drug removed, based on what -- even back then -- was convincing evidence of its dangers. The government's failure to pull the drug years ago, Dr. Wolfe said, "is a serious indictment of the FDA's long-lasting unwillingness to protect people in this country from a deadly but barely effective painkiller… The FDA's deadly delay in this case starkly illustrates how one of the most important public health concepts, the precautionary principle, was embraced by the UK and Europe, but was for too long recklessly rejected by the FDA."
Wolfe also noted that "evidence going back more than 30 years indicates that propoxyphene is not very effective, is toxic at doses not much higher than the recommend dose because a heart-toxic metabolite accumulates in the body, and is somewhat addictive. It has been linked to many thousands of US deaths since 1981, a large proportion of which were likely caused by cardiac toxicity, including the interruption of electrical conduction in the heart."
Public Citizen estimates that between 1,000 to 2,000 people in the US may have died from using propoxyphene in the last few years, since the UK ban was announced. "Our February 2006 petition to the FDA to ban the drug, following the UK ban announcement, did not even result in an FDA advisory committee hearing until we had sued the agency in 2008 to force them to respond to our petition. The subsequent January 2009 FDA advisory committee hearing resulted in a 14-12 vote in favor of banning propoxyphene, despite some FDA efforts to sway the committee against voting for a ban. In July 2009, several weeks after the European Medicines Agency announced its ban, the FDA denied our petition to ban the drug."
Wolfe continued to lash out at the 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 -- which already had enough human evidence of death and near-death in tens of thousands of people to act accordingly."
SOURCES: "Xanodyne agrees to withdraw propoxyphene from the U.S. market" FDA press release, Nov. 19, 2010
"Delayed FDA Removal of Painkiller Propoxyphene (Darvon, Darvocet) From U.S. Market Has Cost More Than 1,000 U.S. Lives," Statement by Dr. Sidney Wolfe, Director, Public Citizen's Health Research Group. Nov. 19, 2010