A new national multicenter study published online in The Journal of Pain found that chronic pain patients who used cannabis daily for one year did not experience an increase in severe side effects compared to those who didn’t use cannabis—also commonly known as marijuana.
Researchers from the Research Institute of McGill University Health Centre (RI-MUHC) in Montreal, Canada analyzed the safety of medical cannabis use in patients with chronic pain from seven pain management–oriented clinics around Canada, including London, Halifax, Fredericton, Toronto, Vancouver, and Montreal (two sites). It is the largest and first-ever study concerning the long-term safety of medical cannabis use by chronic pain patients.
For the study, 215 people with chronic pain were recruited in the marijuana group with 141 current users and 58 former users. The marijuana group was compared with 216 control patients with chronic pain, but who were not using marijuana.
“We found that medical cannabis, when used by patients who are experienced users, and as part of a monitored treatment program for chronic pain over one year, appears to have a reasonable safety profile,” explains the lead author of the study, Dr. Mark Ware.
The medical marijuana used in the study was from a licensed cannabis producer and contained 12.5% tetrahydrocannabinol (THC). A hospital pharmacy dispensed the marijuana on site, and patients collected it every month after completing the required tests and doctor visits. The patients also underwent cognitive and lung function testing, and were also asked about their quality of life, mood, and pain during the one-year follow-up. Many of the patients also completed routine blood test panels for biochemistry and liver and kidney function. There was an average of 2.5 grams of marijuana used overall per day, and it was vaporized, smoked, or eaten.
Researchers also found that marijuana use improved symptoms of distress, pain, quality of life, and mood in the chronic pain patients when compared to the controls. Although the researchers observed no severe side effects, they did report a rise in non-serious side effects in the medical marijuana users, including dizziness, nausea, headaches, drowsiness, and breathing problems linked with smoking.
Sources for Today’s Article:
Ware, M.A., et al., “Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS),” The Journal of Pain 2015, doi: 10.1016/j.jpain.2015.07.014.
“Multicenter study examines safety of medical cannabis in treatment of chronic pain,” ScienceDaily web site, September 29, 2015; http://www.sciencedaily.com/releases/2015/09/150929112036.htm.