Dr Vroom responds

Lucas and Capler argue that PubMed has over 12000 studies on cannabis and that a medical cannabis advisory group has dozens of recent peer-reviewed publications that should enlighten me. Quite the contrary. There are, to date, 13032 articles currently listed under cannabis in the publicly accessible interface to Medline (PubMed.org).

These articles cover topics including biology, recreational use, adverse effects, addiction issues, legal advice, and therapeutic use. The number of randomized controlled trials and meta-analyses, what we as physicians must rely on to cut through the literature “chaff,” is minuscule. Moreover, most of the research is on standardized cannabis formulations rather than smoked cannabis. 

Lucas and Capler also argue that cannabis has been accepted as medicine for thousands of years and therefore should not be considered experimental. Alcohol, foxglove, arsenic, and mercury have in the past also been regarded as “accepted medicines.” Interestingly, during prohibition time, alcohol could only be prescribed for medicinal use. Today, there is no medicinal use for alcohol other than for topical formulations.

Lucas and Capler argue for the use of cannabis for relief of conditions such as MS-related spasticity, chronic pain, and HIV/AIDS. These are specific indications for marijuana as per Health Canada’s Medical Practitioner form B1. However, most physicians would first use a prescription cannabinoid such as tetrahydrocannabinol. The disease prevalence of conditions listed in form B1 should be relatively uniform across Canada.

However, BC authorizations to possess marijuana are nearly one-third of those for the entire country and seven times more per capita than Quebec. I do not think that physicians across Canada are any less educated on “medical marijuana” than BC physicians. More likely this points to the lack of robust evidence-based guidelines as well as a spillover of the highly prevalent use of recreational marijuana in BC. 

Whether Health Canada or the courts created “medical marijuana” is a moot point. Lucas himself points out in the Harm Reduction Journal, 28 January 2008, in his article “Regulating Compassion: An overview of federal medical cannabis policy and practice” that successful legal challenges for marijuana access resulted in “court-ordered compassion” and the resultant introduction by Health Canada of medical access to marijuana. Medical marijuana is not the product of well-orchestrated pharmaceutical research; it is a product of a court decision.

Lastly, sometimes the noise generated from court decisions, voluminous soft evidence, and advocacy promotions leave physicians no option but to reach conclusions from their own experience and observations. This brings me back to the beginning of my initial editorial about my dislike of being confronted by patients requesting particular medications. 

With re­gard to marijuana, in my experience, most patients presenting to physicians’ offices have significant rec­reational marijuana experience and think they may have medical indications for which they may legalize their marijuana use. At the same time, I accept that certain patients do benefit from marijuana, but I would note that ill patients in need of a treatment or drug will always benefit from the comfort and pleasure of a substance or treatment that they enjoyed in the past, be it tobacco, alcohol, or marijuana. 

In conclusion, irrespective of Lucas and Capler’s staunch advocacy work toward legalizing marijuana, I maintain that “medical marijuana” is a substance of unknown composition, potency, or dose administered by smoke inhalation, foisted on the medical profession for us to gate-keep. This substance does not meet standards for rational pharmacotherapy.
—W. Robbert Vroom, MD