Marijuana (Cannabinoids)Pain

Interaction between inhaled cannabinoid and opioids

Cannabinoids and opioids share several pharmacologic properties. They might act synergistically to manage pain, but the safety of the combination isn’t known.

Researchers at the University of California, San Francisco, undertook a study to answer these questions.

First, the details.

  • 21 people with chronic pain were taking twice-daily doses of sustained-release morphine or oxycodone (OxyContin).
  • They were asked to inhale vaporized cannabis in the evening of day 1, 3 times a day on days 2 to 4, and  the morning of day 5.
  • Blood sampling was performed at 12-hour intervals on days 1 and 5.
  • The extent of chronic pain was also assessed daily.

And, the results.

  • There was no significant change in bioavailability of either morphine or oxycodone after exposure to cannabis.
  • Pain was significantly decreased an average of 27% after the addition of vaporized cannabis.

The bottom line?

The authors concluded, “Vaporized cannabis augments the analgesic effects of opioids without significantly altering plasma opioid levels. The combination may allow for opioid treatment at lower doses with fewer side effects.”

Sounds good but how many of these patients were chronic marijuana smokers, and how did their response compare to those who never smoked? In the past, the former group tends to give high grade to cannabis, while the other generally vomits.

Perhaps it’s discussed in the article.

11/29/11 20:56 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.