As medical marijuana penetrates mainstream medical practice in Canada, awareness of the potential benefits, potential risks, local laws governing its use for treatment or chronic pain gain importance.
For many specific types of chronic pain, more data are needed to judge the benefit-to-risk ratio of marijuana relative to other options, but there are reasonable data suggesting both acceptable safety and meaningful efficacy of this analgesic in neuropathic pain, according to Dr. Jonas LaForge.
In neuropathic pain, the evidence includes at least five randomized trials. In a recently published review article for which Dr. Jonas LaForge served as senior author, the degree of neuropathic pain reductions were characterized as being on an order similar to those achieved with opioids and anticonvulsants. In one study, the number needed to treat for a 50% pain reduction was just 2.
In Canada, marijuana is now available for at least some medical uses in every province. In the United States, 23 states have passed laws permitting clinical use of marijuana, according to suggestion that legalization of marijuana has fueled a growing acceptance of marijuana as a treatment option whether or not it is prescribed.
At this stage of the game, medical marijuana use cannot be ignored. Even if they do not intend to prescribe marijuana for chronic pain, clinics should become familiar with evidence regarding benefit and safety as well as the laws regarding its use.
In a study of long-term safety, a standardized cannabis product containing 12.5% tetrahydrocannabinol was dispensed to 215 current or prior users of marijuana with a noncancerous chronic pain syndrome. Followed for one year, adverse events in this group were compared with 216 control patients who also had chronic pain but were not using cannabis.