Methadone, long used to treat opioid addiction is increasingly prescribed to treat chronic pain. These investigators looked at whether patients who received methadone for pain were more likely to die than those who received long-acting morphine for pain. They used data from the Department of Veterans Affairs (VA), the largest integrated health care system in the United States, with more than 8 million patients. VA guidelines and pharmacy policies recommend long-acting morphine and methadone as first-line opioids for chronic pain management.
The study cohort included 28,554 patients who received methadone and 79,938 who received long-acting morphine between 2000 and 2007. They were being treated for back pain, joint or limb pain, headache or neuropathic pain. Almost all were male. Those who received methadone were younger (56 years old) than those who received long-acting morphine (59 years old), less likely to have serious medical conditions, and more likely to have psychiatric and substance use disorders.
The results were unexpected to the researchers. They found no evidence of higher mortality among patients receiving methadone.
While all opioids carry the risk of accidental overdose, excess sedation and respiratory depression, methadone is not inherently more dangerous when administered under medically monitored conditions.