Seven pain clinics across Canada have found smoking medical marijuana to treat chronic pain did not produce any worse serious side effects than abstaining from cannabis, and cannabis use was extremely effective in treating symptoms associated with the condition.
The study took place between 2004 and 2008, and followed 215 adults who suffered from non-cancer related chronic pain and used medical cannabis. Researchers compared this group to a control group of 216 chronic pain sufferers who did not use cannabis for therapy. Both groups found conventional therapies were ineffective. On average, the cannabis users smoked, vaporized, or ingested about 2.5 grams of medical grade marijuana provided by a licensed producer. The marijuana contained 12.5% THC.
While there were no increases in severe side effects (like hospitalizations or death) among cannabis users, there were increases in mild to moderate side effects (like headache, dizziness, nausea, and drowsiness) in the groups that used marijuana, but researchers said that was to be expected. There were no adverse effects found on cognitive function, the kidney, liver, or hormonal function. There were minor effects on lung function that, through further research, could prove to build up over time. That being said, researchers admitted it was difficult to separate the effects of cannabis inhalation from the effects of tobacco use.
Researchers not only looked at the safety of marijuana use, but also at its efficacy, looking at changes in pain, mood, and quality of life. Lead researcher Dr. Mark Ware said, "We found that both groups improved over time, but the cannabis users actually improved significantly more than the control group." These results, which have been published online in The Journal of Pain, not only suggest that marijuana is an effective treatment option, but also a safe treatment option for chronic pain sufferers.
Ware notes the significance of this study, saying it provides clinicians evidence-based guidelines than can use to inform their patients. "That's the big stumbling block that every clinician has: 'I just don't know what to tell my patients.' Well, now you have a detailed listing... and (doctors) can read through every possible side-effect."
Be sure to check out the full article from The Canadian Press for more a more detailed look at this study.