Nearly a third of the deaths caused by prescription painkillers in the U.S. involve methadone and doctors are prescribing the drug too often to treat pain, according to a new report from the Centers for Disease Control.
About 5,000 people died from methadone overdoses in 2009, far more than oxycodone, hydrocodone and other more widely prescribed prescription painkillers. Only 2 percent of prescription painkillers are for methadone.
“Methadone is riskier than other prescription painkillers,” said Thomas Frieden, MD, PhD, director of the CDC. “And we don’t think it has a role in the treatment of acute pain.”
Frieden didn’t stop there. The CDC report warns that there is little evidence that methadone or any opioid should be used to treat pain.
“Methadone and other, extended-release opioids should not be used for mild pain, acute pain, “breakthrough” pain, or on an as-needed basis. For chronic noncancer pain, methadone should not be considered a drug of first choice. This is especially true for conditions for which the benefits of opioids have not been demonstrated, such as headache and low back pain,” Frieden said.
“Only a small fraction of patients with intractable chronic headache treated with opioids experience long-term pain reduction or functional improvement. Evidence that any opioids are effective in chronic low back pain is limited,” Frieden added.
The CDC report said most methadone prescriptions were written by primary-care providers, rather than pain specialists, and called some of the prescriptions “inappropriate.”
According to the FDA, the most common diagnoses associated with methadone were back pain, arthritis and headache. Over four million methadone prescriptions were written for pain in 2009. Nearly a third were for patients who had not taken an opioid in the previous month.
Although methadone overdoses peaked in 2007, Frieden says its use as a painkiller was growing, primarily because it is cheaper than other opioids. Because of its lower cost, methadone is often listed as a preferred drug by insurance companies. He called that “penny wise and pound foolish.”
“All of the evidence suggests that the increase in methadone-related deaths is related to the increased use of methadone to treat pain,” said Frieden, who cautioned that health-care providers who prescribe methadone should have substantial experience with its use and should follow guidelines for appropriate opioid prescribing.
Methadone can cause respiratory depression and disrupt the heart’s rhythm. Taking the drug more than three times a day can cause it to build up in a person’s body. The CDC report also warns that the difference between an appropriate dose of methadone and a dangerous one is small.