The painkillers Darvon and Darvocet, the brand version of the prescription pain medication propoxyphene, are being pulled from the U.S. market because they’ve been blamed for causing lethal heart rhythms, federal regulators said Friday.
Xanodyne Pharmaceuticals Inc., which manufactures the drug, agreed to withdraw the medication at the request of the U.S. Food and Drug Administration, the federal agency said in a press release.
http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm234350.htm
Propoxyphene is an opioid used to treat mild to moderate pain. Xanodyne is based in Newport, Ky.
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 federal agency sought to ban propoxyphene after receiving new clinical data showing that the drug puts patients at risk of potentially serious or even fatal heart rhythm abnormalities, the press release said . As a result of these data, combined with other information, including new epidemiological data, the agency concluded that the risks of the medication outweigh the benefits.
“The FDA is pleased by Xanodyne’s decision to voluntarily remove its products from the U.S. market,” Dr. John Jenkins, director of the Office of New Drugs in the FDA’s Center for Drug Evaluation and Research (CDER), said in a prepared statement. “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.”
The FDA is also advising doctors to stop prescribing propoxyphene to their patients, and patients who are currently taking the drug should contact their health care professional as soon as possible to discuss switching to another pain management therapy.
First approved by the FDA in 1957, propoxophene is sold by prescription under various names both alone (e.g., Darvon) or in combination with acetaminophen (e.g., Darvocet).
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 of the drug.
In January 2009, the FDA held an advisory committee meeting to address the efficacy and safety of propoxyphene. After considering the data submitted with the original drug applications for propoxyphene, as well as subsequent medical literature and postmarketing safety databases, the committee voted 14 to 12 against the continued marketing of propoxyphene products. In making this recommendation, the committee noted that additional information about the drug’s cardiac effects would be relevant in weighing its risks and benefits.
In June 2009, the European Medicines Agency (EMEA) recommended that the marketing authorizations for propoxyphene be withdrawn across the European Union. A phased withdrawal of propoxyphene is under way.
In July 2009, the FDA decided to permit continued marketing, but required that a new boxed warning be added to the drug label alerting patients and health care professionals to the risk of a fatal overdose. In addition, the agency required Xanodyne to conduct a new safety study assessing unanswered questions about the effects of propoxyphene on the heart.
The agency now has reviewed the data from that study, which show that, even when taken at recommended doses, propoxyphene causes significant changes to the electrical activity of the heart. These changes, which can be seen on an electrocardiogram (ECG), can increase the risk for serious abnormal heart rhythms that have been linked to serious adverse effects, including sudden death.
The available data also indicate that the risk of adverse events for any particular patient (even patients who have taken the drug for many years) is subject to change based on small changes in the health status of the patient, such as dehydration, a change in medications, or decreased kidney function.
“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,” Dr. Gerald Dal Pan, CDER director, said in a prepared 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.”
Still at least one group, the Public Citizen, Friday blasted the FDA for taking so long to ban propoxyphene.
http://www.citizen.org/pressroom/pressroomredirect.cfm?ID=3221
“Since the time of the UK announcement in January 2005 of a phased, two-year withdrawal of this drug (which was followed by an immediate steep decline in use), approximately 120 million retail prescriptions have been filled in the U.S. for propoxyphene-containing drugs,” the Public Citizen said in a statement.
“Due to FDA negligence, at least 1,000 to 2,000 or more people in the U.S. have died from using propoxyphene since time the UK ban was announced,” the statement continued. “The best forensic data, the kind relied upon in those countries for the UK and European bans, come from Florida where, because of routine drug testing required by the state medical examiner as part of many autopsies, deaths are categorized as being ’caused’ by certain drugs if the levels found are to be above a certain level. From 2005 through 2009, in Florida alone, 395 deaths were “caused” by propoxyphene. If data from 2007 are representative, in that year, 78 percent of the Florida deaths caused by propoxyphene were ruled accidental.”
The Public Citizen said it will call for a congressional investigation “into whom in the FDA, specifically in the Center for Drug Evaluation and Research, was responsible for the loss of so many lives in this country. It is clear that long before today, many drug safety experts in the Office of Surveillance and Epidemiology had decided the drug should be removed from the market.”
