Can Cannabis Reduce Prescription Opioid Use?

A new study suggests that smoking cannabis may lower the amount of prescription opioids needed to produce pain relief.

The findings were published in Neuropsychopharmacology on February 20, 2018.

“Clinicians are looking for strategies to decrease opioid use to the lowest possible dose while still ensuring adequate pain relief,” said Ziva Cooper, PhD, associate professor of clinical neurobiology (in psychiatry) at the Columbia University Vagelos College of Physicians and Surgeons and lead author of the study.

Previous studies, in animal models, have suggested that cannabis may decrease the amount of opioid medication needed for pain relief. But the combination hasn’t been studied under controlled conditions in humans.

For this placebo-controlled, double-blind study, 18 regular cannabis smokers were given either 2.5 mg—half the lowest dose prescribed for pain relief—or 5 mg of oxycodone or placebo while smoking cannabis. They then used a model of pain testing that has predictive validity for analgesics used therapeutically in which a hand is immersed in cold water and removed when the patient begins to feel pain. Pain relief—time until pain was experienced and the amount of time the pain was tolerated before withdrawing the hand—was assessed several times over 3 hours. The participants repeated this experiment six times over the next several weeks, with a different drug combination in each session. They also measured the how the cannabis and opioid combination affected the abuse potential of each drug.

Not surprisingly, the 5 mg opioid dose—the lowest dose prescribed for pain relief—by itself, reduced pain. While the 2.5 mg opioid dose alone did not reduce pain, combining it with active cannabis produced pain relief comparable to the 5 mg dose alone.

No changes in cannabis’s intoxication or abuse potential were detected. However, participants who took low-dose oxycodone and active cannabis were more likely to report positive subjective ratings of oxycodone.

“Findings from observational studies have suggested that problematic prescription opioid use has been greatest among patients with chronic pain,” said Cooper. “Additional studies in chronic pain patients are needed to determine the abuse potential of low-dose oxycodone when combined with cannabis. It is also critical to study the analgesic effects of low-dose oxycodone when combined with forms of cannabis that are not smoked.”

The study is titled “Impact of co-administration of oxycodone and smoked cannabis on analgesia and abuse liability.” The authors include Ziva Cooper (Columbia University Irving Medical Center, New York, NY), Margaret Haney (CUIMC), Sandra D Comer (CUIMC), Rebecca Balter (CUIMC), Divya Ramesh (Center for Advancement in Managing Pain, University of Connecticut School of Nursing), and Gillinder Bedi (Orygen National Centre Of Excellence In Youth Mental Health and University Of Melbourne).


This research was supported by US National Institute on Drug Abuse DA19239,

DA09236, and DA027755. Dr. Cooper and Dr. Haney’s research is funded by NIDA. They receive partial salary support for investigator-initiated studies from Insys Therapeutics, Inc.


The authors report no conflicts of interest relating to the subject of this study.




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