FDA, on Tuesday, announced that new data showed an increased chance of overdose in patients who use medications containing propoxyphene (used since the 1950s in products such as Darvon and Darvocet, among others) to treat mild to moderate pain.
In January, an FDA advisory board voted 14 to 12 to ban use of the drugs altogether, but FDA declared them an acceptable option, though with increased warnings. To reduce the likelihood of overdose, FDA is now asking manufacturers to strengthen the language in labels, add a boxed warning, and include a medication guide with each prescription or refill.
Additionally, drug firms must conduct a safety study to determine how propoxyphene affects patients’ hearts when taken at higher-than-recommended doses. Xanodyne, manufacturer of Darvon and Darvocet, was issued a letter indicating the need for a required study.
Both the Centers for Medicare & Medicaid Services and the Veterans Health Administration will also contribute data and help study why the drug is leading to overdose.
CDER Director Janet Woodcock cited a study in Scotland that found that the rate of fatality from overdose was high, and data from a Florida medical examiner that showed a correlation between propoxyphene overdose and death.
“Many of the overdoses were intentional ingestions, of which there are slightly different patterns in Europe than in the United States,” Woodcock said at a press conference. “In the US, we typically see multi-drug overdoses, which makes it very difficult to sort out what’s doing what.”
From 1969 through 2005, there have been 91 deaths reported in the AIRS database from persons taking propoxyphene, the majority of which have been overdoses and suicide attempts. Most overdoses, however, involved multiple drugs.
In related news, FDA denied a petition from the public interest group Public Citizen requesting a phased withdrawal of propoxyphene, according to Woodcock. “The reason for the denial is that FDA determined that propoxyphene is an acceptable option for pain relief at recommended doses, given the alternatives,” she said.