Cannabis Boosts Effect of Opioids for Chronic Pain Relief

Patient Expert

A new study, published in the December issue of Clinical Pharmacology & Therapeutics, suggests that adding a cannabinoid to opioid therapy may result in greater relief of chronic pain at lower opioid doses.

Study Design and Results

Twenty-one individuals with chronic pain, who took twice-daily doses of sustained-release morphine or oxycodone, were enrolled in the study and admitted for a five-day inpatient stay.   The chronic pain conditions represented included non-specific musculoskeletal pain, post-traumatic pain, arthritis, peripheral neuropathy, fibromyalgia, migraine, multiple sclerosis, sickle cell disease and thoracic outlet syndrome.

Participants were asked to inhale vaporized cannabis (marijuana) in the evening of day one, three times a day on days two through four, and in the morning of day five.   Blood sampling was performed at 12-hour intervals on days one and five.   Chronic pain levels were assessed daily.

Investigators found that there was no significant change in the area under the plasma concentration-time curves for either morphine or oxycodone after exposure to cannabis.   In fact, the morphine levels were slightly lower with cannabis.

What is really interesting is that despite opioid levels being the same or lower with cannabis, patients experienced greater pain relief, reporting an average of 27 percent less pain.

The researchers concluded, "that 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."

My Thoughts...

I've long thought that cannabis has great potential as a pain reliever.   The sad thing is that the US government makes it extremely difficult for researchers to study medical marijuana legally.

In my opinion, the results of this study certainly justify additional research into the use of cannabis as a way to reduce the amount of opioids needed to provide pain relief.   I'd like to see larger studies as well as controlled, randomized clinical trials.

Warning:   I know studies like this make it very tempting to try adding cannabis to your current opioid treatment in hopes of greater pain relief, but please do not try mixing opioids and marijuana on your own.   Although this study has very   encouraging results, it was much too small to draw broad conclusions about safety and efficacy.

Another important factor to consider is that if you have signed a treatment agreement and/or your doctor ever tests you for drugs, having marijuana in your system could result in your doctor refusing to continue prescribing opioids for your pain.

The marijuana used in this study was mainly delta-9-tetrahydrocannabinol or THC (the active chemical in cannabis).   There are currently two FDA-approved drugs containing synthetic THC - Marinol and Cesamet - however, these drugs were not used in the study so we can't draw any conclusions as to how they might interact with opioids taken concurrently.

Abrams DI, et al. "Cannabinoid-Opioid Interaction in Chronic Pain." Clin Pharmacol Ther. 2011;90:844-851.