Darvon, Darvocet Banned
Controversial Painkiller Sunk by Dangerous Heart Side Effects
By Daniel J. DeNoon
WebMD Health News
Reviewed by Louise Chang, MD

Nov. 19, 2010 -- The FDA has at last banned Darvon, Darvocet, and other brand/generic drugs containing propoxyphene -- a safety-plagued painkiller from the 1950s.

New proof of heart side effects, in studies of healthy people taking normal doses of the drug, prompted the FDA to act.

An estimated 10 million Americans are taking Darvocet and other propoxyphene painkillers. They should NOT immediately stop taking the drugs, as there is danger of serious withdrawal symptoms.

Patients taking the drugs should instead immediately contact their doctors for help switching to different methods of pain control.

"Don't delay," warns Gerald Dal Pan, MD, MHS, director of the FDA's office of surveillance and epidemiology.

The FDA action comes nearly six years after the drug was banned in the U.K., and nearly a year and a half after the European drug agency banned it.

The public interest group Public Citizen petitioned the FDA to ban the drug in 1978 and again in 2006. The latter petition caused the FDA to take the matter to an expert advisory committee, which in July 2009 voted 14-12 to ban the drug.

But the FDA overruled the panel, instead asking Darvon/Darvocet maker Xanodyne Pharmaceuticals Inc. to conduct studies of the drug's effects on the heart. The results of those studies led to the FDA ban.

"The drug puts patients at risk of abnormal or even fatal heart rhythm abnormalities," John Jenkins, MD, director of the FDA's office of new drugs at the Center for Drug Evaluation and Research, said at a news conference. "Combined with prior safety data, this altered our risk assessment."

The FDA ban comes too late for Public Citizen, which blasted the FDA for waiting far too long to protect the public.

"Due to FDA negligence, at least 1,000 to 2,000 or more people in the U.S. have died from using propoxyphene since the time the U.K. ban was announced," Sidney Wolfe, director of Public Citizen's health research group, says in a news release.

Wolfe says Public Citizen will call for a congressional investigation into who at the FDA "was responsible for the loss of so many lives in this country."

Jenkins says although it's impossible to know exactly how many deaths are linked to propoxyphene, an FDA study shows that more deaths are linked to the drug than to either of two alternative opioid painkillers, tramadol and hydrocodone.

Dal Pan says that people who have taken Darvocet, Darvon, or other propoxyphene drugs for a long time are not at increased risk of heart problems.

"Long-term users should not worry: The heart effects are not cumulative," he says. "Once people stop using propoxyphene, the side effects should go away."

More information about the propoxyphene ban is available on the FDA web site -- including, for the first time, a video news release.