Cannabis administration significantly augments the analgesic effects of opiates in patients with chronic pain, according to clinical trial data published online in the journal Clinical Pharmacology & Therapeutics.

Investigators at the University of California, San Francisco assessed the use of vaporized cannabis over a five-day period in 21 chronic pain subjects who were on a regimen of twice-daily doses morphine or oxycodone. Participants in the trial inhaled cannabis vapor on the evening of day 1 of the study, three times a day on days 2 through 4, and in the morning of day 5. Subjects’ extent of chronic pain was assessed daily.

Researchers determined that subjects’ pain “was significantly decreased after the addition of vaporized cannabis” and surmised that cannabis-specific interventions “may allow for opioid treatment at lower doses with fewer [patient] side effects.”

They concluded: “The participants experienced less pain after 5 days of inhaling vaporized cannabis; when the morphine and oxycodone groups were combined, this reduction in pain was significant. This is the first human study to demonstrate that inhaled cannabis safely augments the analgesic effects of opioids. … These results suggest that further controlled studies of the synergistic interaction between cannabinoids and opioids are warranted.”

For more information, please contact Paul Armentano, NORML Deputy Director, at: paul@norml.org. Full text of the study, “Cannabinoid-Opioid interaction in chronic pain,” appears in Clinical Pharmacology & Therapeutics.