The U.S. Food and Drug Administration is taking several actions to reduce the risk of overdose in patients using pain medications such as Darvon and Darvocet that contain propoxyphene. The actions were taken because of data linking propoxyphene and fatal overdoses.
The agency is requiring manufacturers of propoxyphene-containing products to strengthen the label, including the boxed warning, emphasizing the potential for overdose when using these products. These manufacturers will also be required to provide a medication guide to patients stressing the importance of using the drugs as directed.
In addition, the FDA is requiring a new safety study assessing unanswered questions about the effects of propoxyphene on the heart at higher than recommended doses. Findings from this study, as well as other data, could lead to additional regulatory action.
“Physicians need to be aware of the risk of overdose when prescribing these drugs. They should carefully review patient histories and make appropriate treatment decisions based on the warnings and directions stated within the drug’s label,” said Janet Woodcock, M.D, director of the FDA’s Center for Drug Evaluation and Research. “Prescribers and patients should be aware of propoxyphene’s potential risks when used at doses higher than those recommended. Therefore, the FDA is requiring manufacturers to provide more information to help physicians and patients decide whether propoxyphene is the appropriate pain therapy.”
To further evaluate the safety of propoxyphene, the FDA plans to work with several groups including the Centers for Medicare & Medicaid Services and the Veterans Health Administration to study how often the elderly are prescribed propoxyphene instead of other pain relievers and the difference in the safety profiles of propoxyphene compared to other drugs.
Propoxyphene manufacturers are required to submit the requested safety labeling changes to the FDA within 30 days, or to provide a reason why they do not believe such changes are necessary. If they do not submit new language, or if the FDA disagrees with the language the companies propose, the Food, Drug, and Cosmetic Act provides strict timelines for discussions regarding the changes. At the end of these discussions, the FDA may issue an order directing the labeling changes as deemed appropriate to address the new safety information.
Also today, the FDA denied a citizen petition from the public interest group Public Citizen requesting a phased withdrawal of propoxyphene. The agency said in its response that despite the FDA’s serious concerns about propoxyphene, the benefits of using the medication for pain relief at recommended doses outweighs the safety risks at this time. The FDA also noted that it plans to further evaluate the safety of propoxyphene and will take additional regulatory action if necessary.
Propoxyphene has been on the market since 1957. It is a widely prescribed member of a group of drugs known as opioids and is used as a treatment for mild to moderate pain.
The most frequent side effects of propoxyphene include lightheadedness, dizziness, sedation, nausea, and vomiting.