It has been a tough few months for pain medications—both prescription and over the counter. In late June, a Food and Drug Administration advisory panel recommended lowering the maximum daily dose of acetaminophen, the ingredient found in Tylenol and many other over-the-counter and prescription medications, because liver damage can occur if people take too much of it. And earlier this month, the FDA ordered manufacturers of pain medications containing an ingredient called propoxyphene to strengthen the drug labels, including a boxed warning that emphasizes the potential for overdose in people taking these pain medications, which include the older pain drugs Darvon and Darvocet.
This news has left some consumers scratching their heads about which pain medications to take, doctors say. "The key thing is that the public has been getting very, very mixed messages" about painkillers lately, says Scott Fishman, past president of the American Academy of Pain Medicine and president of the American Pain Foundation, a patient organization. According to several experts, here's what consumers need to know about these pain medications:
* The commonly used propoxyphene-containing medications Darvon (propoxyphene) and Darvocet (a combination of propoxyphene and acetaminophen) are typically used to treat "mild-to-moderate, usually acute pain," says Paul Christo, director of the multidisciplinary pain fellowship program at the Johns Hopkins University School of Medicine. A primary reason for concern with these medications stems from a possible increased risk of fatal overdose, according to the FDA. There is evidence of both accidental and intentional fatal overdoses from propoxyphene, and some European research suggests that this drug may be more deadly when too much is taken than other types of pain medications. There are also "fairly high quality studies that demonstrate that propoxyphene is no more effective than aspirin or acetaminophen," Christo says.
Despite these concerns, the FDA recently denied a citizen's petition from Public Citizen, a consumer advocacy organization (and went against its own advisory panel's 14-to-12 vote), in favor of a phased withdrawal of propoxyphene from the market. The agency says that there is evidence that the drug effectively treats pain when taken at recommended doses. Some doctors say they are glad that the FDA has not withdrawn propoxyphene, because that means people in pain have more options for treatment. "One of the controversies is you don't want to take away options for people who can't tolerate Vicodin or other stronger medications," says Rollin Gallagher, president of the American Academy of Pain Medicine and clinical professor of psychiatry and anesthesiology in pain medicine at the University of Pennsylvania. The key here, he says, is to spend time with your doctors asking questions, writing things down, and really understanding how to properly take medications.
In addition to requiring a beefed-up label for these medications—which the manufacturers must submit within 30 days of the July 7 announcement (or state why they don't think labeling changes are necessary)—the FDA is ordering a new study to look into how propoxyphene affects the heart at higher-than-recommended dosages. The agency says that this could lead to regulatory action, depending on the findings. "The issue is that, in rare cases, it can affect the heart rhythm in a deadly way," Fishman says. The FDA says it intends to collaborate with the Centers for Medicare and Medicaid Services and the Veterans Health Administration to study how often elderly people take propoxyphene instead of other types of pain medications and the difference in safety between these medications and other pain medications.
Cynthia Reilly, director of the practice development division at the American Society of Health-System Pharmacists, says the organization was disappointed that the FDA did not pull propoxyphene from the market. "We testified, calling for market withdrawal [because of] safety concerns with propoxyphene," she says. "Considering the number of other options, and considering the safety and effectiveness concerns, we would've hoped that it would've been withdrawn from the market."
In prepared written testimony for a statement given before the FDA in January, Reilly cited research that she says demonstrates that propoxyphene has a poor record of effectiveness. Among the research she cited was a meta-analysis of 26 studies involving 2,231 patients who had postoperative, arthritis, or musculoskeletal pain that compared the effectiveness of acetaminophen plus propoxyphene and the effectiveness of acetaminophen taken alone or with a placebo. The findings showed that adding propoxyphene was no more effective than taking acetaminophen alone. Another study she cited involved patients with moderate to severe postoperative pain; it found that a propoxyphene-acetaminophen combination was about as effective as another pain medication called tramadol but was less effective than ibuprofen.