In a number of earlier articles, we have considered the effectiveness of cannabis-based products in the treatment of chronic pain. In light of the largely positive way in which their increasingly greater availability has been received, some surprising conclusions have been reported in a recent Cochrane Review*.
The review examined 16 randomised double-blind controlled studies into “the efficacy, tolerability, and safety of cannabis-based medicines…compared to placebo or conventional drugs for conditions with chronic neuropathic pain in adults.”
The 16 studies investigated in the review involved a total of 1,750 participants and evaluated a variety of cannabis products including herbal cannabis, sprays and tablets. The products used either synthetic or plant-derived ingredients.
In a surprise to many, the reviewers concluded that the effectiveness of cannabis-based products for treating the symptoms of chronic neuropathic pain was not supported by the available evidence. Further, such benefits that were seen were outweighed by the potential for psychiatric and neurological side effects.
In conclusion, the reviewers said “Since relatively few participants achieve a worthwhile response with cannabis-based medicines, decisions to use these medicines may require stopping rules to avoid the unnecessary exposure to harms in the absence of benefit.”
* In their own words: “Cochrane Reviews are systematic reviews of primary research in human health care and health policy, and are internationally recognized as the highest standard in evidence-based health care resources. They investigate the effects of interventions for prevention, treatment, and rehabilitation.”