Cannabis Safety for Chronic Pain

medical cannabisAccording to the American Academy of Pain Medicine, 1.5 billion people worldwide suffer from chronic pain. Medical cannabis has shown promising potential as a daily treatment for managing chronic pain. A new study published online in The Journal of Pain testifies that medical cannabis, when monitored carefully and given daily, is overall safe and doesn’t increase the risk of serious adverse events.

The study, conducted by a Canadian research team from the Research Institute of the McGill University Health Centre (RI-MUHC), is the first to examine medical cannabis safety when taken long term for pain management. Researchers followed 431 patients participating in a nationwide study launched in 2004: Cannabis for the Management of Pain: Assessment of Safety Study (COMPASS). The study incorporated seven expert pain management centers across Canada.

The treatment group consisted of 215 adults who used medical cannabis daily to manage their non-cancer chronic pain, at an average of 2.5 grams a day either smoked, vaporized, or eaten. Patients received herbal cannabis with 12.5% THC from a licensed cannabis producer and dispensed by their hospital pharmacy once a month after a required visit and tests. Doctors measured for side effects with lung function and cognitive tests, and patients were asked about their pain levels, moods, and quality of life every month for a year. Many patients also underwent complete panels of blood tests that checked routine biochemistry, liver and kidney function, and selected hormone levels.

Results were compared to those of the control group, which was made up of 216 chronic pain sufferers who did not use medical cannabis to manage their pain. Patients who smoked medical cannabis daily exhibited no greater risk of experiencing serious adverse side effects than non-cannabis users. Tests also showed no deleterious effects on brain function. There was, however, a notable lessening in pain severity and symptom distress, and an overall improvement in quality of life compared to patients in the control group.

But, and depending on the patient this could be a big but: daily use of medical cannabis did increase the risk of non-serious side effects, including headaches, nausea, sleepiness, dizziness, and respiratory problems linked to smoking.

It’s also important to stress that cannabis use was carefully monitored, and that the patients for the most part were experienced users. Lead researcher Dr. Mark Ware explains, “What we are seeing is that it appears to be a relatively safe drug when used by people who have already determined that it helps them. We cannot draw conclusions about safety issues of new cannabis users.”