A McMaster University-led study has found that marijuana cannot be used as an “exit” or replacement drug to get people off opioids.
The study also found that using cannabis while on methadone to treat opioid addictions makes no difference on the effectiveness of the treatment.
It’s disappointing to those who hoped pot could replace opioids among addicts and do less harm.
The study, published in the Canadian Medical Association Journal on Tuesday, was done by a research team that analyzed other studies on the effects of cannabis on illicit opioid use during methadone therapy, a common treatment for opioid addictions.
Dr. Zainab Samaan, one of four McMaster researchers on the study, said the idea of replacing opioids with cannabis has come from the U.S. mainly, but the review of six already-published studies involving 3,600 participants shows: “from our finding, that cannabis made no difference.”
“We found that using cannabis in addition to opioids didn’t help reduce opioid use,” she said.
The study was funded by the Canadian Institutes of Health Research.
Samaan, a psychiatrist at St. Joseph’s Healthcare Hamilton and an associate McMaster professor, said the findings also shows cannabis had no effect on helping people stop or get out of using opioids.
“There was a perception that cannabis can help with opioid withdrawal,” she explained. Or, that cannabis could help with the opioid addiction treatment, she added.
But the study appears to disprove that perception.
A Guardian newspaper article in April says data on marijuana being an “exit drug” that can help ease the opioids crisis is scarce, but adds that “the anecdotes are plentiful.”
In August, it was reported that in Illinois it became possible for patients who had been prescribed opioids to opt for medical marijuana instead.
But since the McMaster-led study showed no evidence of pot use reducing opioid use, Samaan and her fellow researchers are now designing a new study to examine why those with opioid addictions also use marijuana, and if there are any benefits or harm to doing so.