The U.S. Food and Drug Administration (FDA) asked the makers of drugs that contain propoxyphene the opioid painkiller propoxyphene, sold under the brand names Darvocet or Darvon, in 2010 to voluntarily withdraw them from the market due to new evidence that they cause potentially fatal heart problems.
Xanodyne Pharmaceuticals Inc., maker of Darvon and Darvocet, which combines Darvon with acetaminophen, agreed to withdraw the medicines from pharmacy shelves. The FDA has asked makers of generic propoxyphene to do the same.
Propoxyphene has been around a long time; the FDA approved the opioid in 1957. “I think people liked it because people viewed it as not quite as strong as others [in its class], so it fit in for mild to moderate pain, not severe pain,” says David Pisetsky, MD, a professor of medicine at Duke University Medical Center in Durham, N.C.
But the drug hasn’t been without controversy. The FDA denied two public citizens’ petitions, in 1978 and in 2006, to ban the drug due to health risks. The government agency said medical reviews consistently found that the benefits outweighed its risks. In 2009, however, the FDA called for a stronger boxed warning on propoxyphene drugs and required Xanodyne to conduct a safety study to further look into the effects of propoxyphene on the heart.
Britain pulled the drugs five years ago because of concerns about the medication’s link to suicides and accidental overdoses. The rest of Europe did the same last year. But the FDA says it didn’t believe action was warranted until it received the results of the new safety study, which showed propoxyphene caused a risk of severe and potentially fatal heart damage and heart rhythm abnormalities.
“The data suggested that the heart risk of propoxyphene could apply to all users, and not just those who took excessive doses or those with medical conditions that might reduce their ability to clear propoxyphene from the body, such as patients with reduced kidney function,” explains John Jenkins, MD, director of the FDA Center for Drug Evaluation and Research. “I think what is unique here is that the new heart data show that the adverse effects on the electrical activity of the heart occur at recommended doses in normal volunteers and not just in overdose.”
The FDA is advising health care professionals to stop prescribing propoxyphene to their patients. The FDA says patients will no longer be at risk when they stop the medication, but need to consult a doctor before doing so.
Dr. Pisetsky says patients have other pain-management options. “This was not a unique product. There are certainly many, many opioids out there that can be used.”
Dr. Pisetsky says patients should talk with their own doctors to assess side effects of other medications and figure out what’s best for them.
“It’s important that physicians and patients have conversations,” Dr. Pisetsky says. “There’s a large menu of things you can try short of medication. And then with medication, you look at what’s the safest and most effective product you can prescribe.”