Methadone is a synthetic opioid which has been used for a long time as an “anti-addictive”, an alternative to drugs like heroin. While many who treat opioid addicts have switched to using drugs like Suboxone, methadone is still used as an analgesic for treating pain – both inside and out of the hospital. However, the use of methadone unsupervised for treating pain may be especially dangerous.
A new study from Vanderbilt University Medical Center has found that using methadone to treat pain carries a 46 percent increased risk of death outside of a hospital setting, when compared to the morphine SR (sustained release), Science Daily reports.
“That’s quite high by medical standards. And as far as we know, there’s no clinical benefit to using methadone as opposed to morphine SR, so for that reason these deaths are particularly concerning,” said the study’s first author, Wayne Ray, Ph.D., M.S., professor of Health Policy. “It’s a lot of increased risk for a drug that happens to be cheap, but confers no other benefits.”
In 2009, there were about 4.4 million methadone prescriptions written for pain management, according to the article. The researchers found that, when compared to morphine SR, methadone’s higher risk ratio is 72 excess deaths per every 10,000 person-years of treatment.
All opioid medications carry with them side effects, one of those being repressed respiration. What separates methadone from other opioids regarding the aforementioned side effect is that the drugs analgesic effect is more short-lived than the respiration effect.
“This means that patients may sense the need for more medication even though there is still enough methadone in their bodies to cause respiratory problems, so they essentially inadvertently overdose themselves,” Ray said.
In 2006, the Food and Drug Administration and the Centers for Disease Control and Prevention recommended against using methadone as a first-line treatment for pain, the article reports. The authors of the new study wrote that their findings “support recommendations that methadone should not be considered a drug of first choice for non-cancer pain.”
Even when methadone was prescribed in low doses the risks were still high.
“That’s what’s interesting,” Ray said, “because this is consistent with the potential of methadone to accumulate and for patients to inadvertently overdose themselves. Apparently the higher you go with the dose, the less difference there is between methadone and another opioid. That’s what’s particularly concerning in some ways: that a clinician might consider the low dose to be relatively free of overdose risk, but because of methadone’s particular pharmacologic properties that may be incorrect.”
The findings can be seen in JAMA Internal Medicine.