Methadone is increasingly being used by physicians to manage chronic pain, but it is a risky drug to prescribe as a pain reliever, according to an article published in the Journal of the American Medical Association (JAMA).
The article cites a recent study by the Centers for Disease Control and Prevention (CDC), which found that methadone was involved in over 30 percent of overdose deaths linked to painkillers, even though the drug makes up only about 2% of painkiller prescriptions. Over 5,000 methadone overdose deaths occur annually — more than the combined overdose deaths caused by cocaine or heroin.
Part of methadone’s appeal is its low cost. Many states and insurance companies list methadone as the preferred opioid medication in their formularies. Methadone-related deaths surged in Washington after the state began encouraging patients in its health care system to use the drug, according to an investigation by the Seattle Times.
Other painkillers, such as OxyContin, have a short half-life and dissipate in a persons’ system in a few hours. Methadone, on the other hand, can linger in the bloodstream for days. Methadone has a half-life that’s both long and hard-to-predict. This can lead to toxic levels of methadone building up in a patients’ system and causing respiratory depression. With little or no warning, a patient can fall asleep – never to wake up again.
In addition, methadone may interact with anti-anxiety medications, which patients suffering from pain often take and frequently abuse.
“Many physicians, who are well meaning, don’t know how to use methadone,” said Lewis Nelson, an emergency physician and medical toxicologist at New York University School of Medicine.
Methadone has been used successfully for more than 40 years as a treatment for heroin addiction and it is increasingly being prescribed to manage pain. In 2009 alone, methadone prescriptions exceeded 4 million, reports the CDC. The increase in prescriptions coincided with the rise in its overdose deaths.
Both Nelson and CDC director Thomas Friedman advise physicians to avoid prescribing methadone to treat chronic non-cancer pain or acute pain. Rather, doctors should consider other treatment options, including safer opioid medications.“These drugs must be treated with a healthy respect,” Nelson told JAMA. “I don’t think methadone should be used for chronic [non-cancer] pain. It’s the least safe option.”