Propoxyphene Pulled From US Market

Following new clinical data and a request from the FDA, Xanodyne Pharmaceuticals has agreed to withdraw its prescription pain products Darvon and Darvocet (propoxyphene) from the US market. The FDA has also requested generic manufacturers of propoxyphene-containing medicines to voluntarily withdraw their products too.

The actions were taken because of the release of clinical data showing that the drug puts patients at risk of potentially serious or even fatal heart rhythm abnormalities. As such, the FDA concluded that the benefits of the medication do not outweigh the risks and has advised healthcare professionals to stop prescribing it.

The FDA had previously examined the efficacy and safety of the medication in January 2009 where an advisory committee voted 14 to 12 against the continued marketing of propoxyphene-containing products. However, the committee also believed that additional information about the drug’s cardiac effects would be relevant in weighing its risks and benefits. In July 2009, the FDA decided to permit continued marketing, but required a new boxed warning to be added to the drug. Additionally, the FDA requested Xanodyne to conduct a new safety study.

“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,” Gerald Dal Pan, Director of the Office of Surveillance and Epidemiology at the FDA’s CDER, said in a statement. “However, long-time users of the drug need to know that these changes to the heart’s electrical activity are not cumulative. Once patients stop taking propoxyphene, the risk will go away.”

In the EU, a phased withdrawal of propoxyphene is already underway. The European Medicines Agency (EMA) recommended in June 2009 that marketing authorizations for the medication be withdrawn across the EU.

www.fda.gov