A Food and Drug Administration panel of medical experts narrowly recommended Friday pain pills commonly known as Darvon and Darvocet should be pulled off the market over concerns the drugs don't work very well and carry safety risks.

The panel narrowly said, in a 14 to 12 vote, the benefits of the decades-old drugs didn't outweigh the risks and they should be removed from the U.S. market. However, the FDA will make the final decision, and given the essentially split vote it's not clear the FDA will take the products off the market.

Sharon Hertz, the deputy director of FDA's anesthesia, analgesia and rheumatology products division, said the agency would also look at whether it could order post-market studies or change the drugs' labels.

The advisory panel meeting was prompted by a petition and then lawsuit from Public Citizen, a public-advocacy organization, that has asked the agency to remove the products from the market because there's little evidence the drugs are effective and they carry risks of death from heart problems.

Darvon, which contains the active ingredient propoxyphene, has been on the U.S. market for more than 50 years and was developed by Eli Lilly & Co. (LLY). Later, the company combined propoxyphene with another pain ingredient, acetaminophen, and sold the pill as Darvocet.

Both drugs are now marketed by private, generic-drug makers including Xanodyne Pharmaceuticals Inc. of Newport, Ky., and Qualitest/Vintage Pharmaceuticals, of Huntsville, Ala. More than 20 million prescriptions were written for the products containing propoxyphene in 2007, according to the FDA. The companies said the products were safe and effective when used as directed.

James B. Jones, Xanodyne's vice president for medical affairs said the company would discuss the panel meeting with the FDA "and come up with a plan on how to move forward."

The products are approved to treat mild to moderate pain. But like certain other classes of pain medications, propoxyphene products can be addictive and have been linked to deaths in patients, especially when used with alcohol and other drugs, and the drug labels' currently warn of those risks.

In its petition, Public Citizen cited data from the Drug Abuse Warning Network, which uses a sample of nationwide autopsy information from medical examiners - implicating propoxyphene in 5.6% of drug-related deaths from 1981 to 1999. Public Citizen also said the network reported 2,110 accidental deaths related to propoxyphene over the same period.

In a presentation before the advisory panel Friday, Dr. Sidney Wolfe, director Public Citizen's health research group, presented updated data from the drug-abuse network, which showed 503 deaths in which propoxyphene was listed as a contributing factor in 2007.

"All drugs have risks," Wolfe said. "If they don't have benefits they need to come off the market."

In a presentation to the panel, the FDA said some of the original studies of the drugs showed they had "weak" effects. In documents prepared for the panel meeting, however, the FDA questioned whether they had enough evidence of safety problems to warrant removal of the products.

In 2005, U.K. health authorities said the benefits of the drugs didn't outweigh the risks and announced a phased withdrawal of the products over a three-year period, and in 2006 Public Citizen filed a petition with FDA to remove the products.

Last year, Public Citizen sued the FDA for failure to act on its 2006 petition, which prompted Friday's advisory panel meeting.

The petition said the products should be removed from the market because they are "relatively weak" painkillers and said "toxicity develops at only slightly above the recommended daily dose."

The FDA said a review of its adverse-event reporting data base showed 3,028 serious and non-serious reports from 1957 through Sept. 24, 2008, associated with propoxyphene. Of those, 2,136 reports were considered serious and included 1,452 deaths. Many of the serious-event reports included reports of suicides, intentional drug overdoses, heart attacks and unintentional drug overdoses, the FDA said. The agency said some of the serious adverse-event reports also listed more than one type of drug.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; jennifer.corbett@dowjones.com

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