A patient approaches you with severe rheumatoid arthritis and what she describes as horrible, persistent pain that has not responded to her rheumatologist’s prescribed therapies. She asks you to prescribe marijuana. Your response is:
a) I can’t – it’s illegal to prescribe marijuana
b) I can but I will have to charge $100 for the counseling required for you to understand the use of this effective therapy
c) You can just grow it yourself and use it as needed
d) I am not convinced of its benefit and there are no data showing its safety and effectiveness for your condition so I won’t prescribe it
So, Doctor, what is your response to this distressed patient?
There is a groundswell of lobbying by motivated patients with chronic pain syndromes for the use of marijuana as a drug. Although oral cannabinoids are used for treating nausea in cancer patients, the most common basis for a request for medical marijuana in Canada is arthritis pain.
As of June 2013, estimates from the office of the Information Commissioner of Canada list severe arthritis as the reason the 65% of Canadians who are allowed to possess marijuana for medicinal purposes.
Dr. Fitzcharles, a McGill rheumatologist, has a paper accepted for publication in Arthritis Care & Research, entitled The Dilemma of Medical Marijuana use by Rheumatology Patients, which reviews the topic. It is not a randomized trial; it is, however, a thoughtful review of the literature. Remarkably, despite arthritis being the major reason marijuana is prescribed, Dr. Fitzcharles indicates there are no trials showing benefit of the drug in arthritis, although she acknowledges some evidence for the relief of pain and nausea in cancer patients and some benefit in neuropathic pain. In fairness, she notes a positive trial of nabiximol, a synthetic analogue of THC (Sativex®). This was a randomized clinical trial of 58 patients with rheumatoid arthritis over a five week period, and showed improvement in pain and quality of sleep, efficacy, tolerability and safety of a cannabis-based medicine in the treatment of pain caused by rheumatoid arthritis.
This thoughtful commentary calls to mind the need for approval of any drug – whether it grows in a field or is synthesized in a lab – through a process of clinical testing that ultimately is confirmed through a randomized, placebo controlled double blind trial.
In the paper, the authors point out the biological plausibility of marijuana as a drug, albeit a dirty drug, with many off target effects if taken as commonly used: in the form of a cigarette. Humans are well prepared to desire marijuana. We have several receptors in our endocannabinoid system and activating these pathways induces many effects, from sedation and euphoria to suppression of nausea to less desirable effects on mood and memory. Marijuana (the plant) contains 450 plus compounds and 70 phytocannabinoids, two of which have particular medical interest. Dr. Fitzcharles notes that the precursor of delta-9- tetrahydrocannabinol (THC), transformed by heat into THC, has psychoactive and pain relieving properties. Its less avidly binding cousin, cannabidiol, might counteract the negative effects of THC on memory, mood and cognition.
The Department of Medicine’s own Dr. Chris Simpson (right), President-elect of the Canadian Medical Association, was recently interviewed on Canada AM by Beverly Thompson. He raised the issue that Canadian physicians are being asked to serve as informal gatekeepers to provide Medical Marijuana when health Canada has not really approved the drug with the rigor required for approval of all other drugs. He notes 40,000 users already have access to the drug but the route forward is unclear. Simpson cites the need for randomized controlled trials rather than anecdotal evidence.
Dr. Simpson’s assessment is very similar to the opinion I received from one of Queen’s University’s outstanding rheumatologists, Dr. Mala Joneja (left). Dr. Joneja expressed her concerns about the absence of evidence of either efficacy or safety – or for that matter, guidance on dosing and surveillance. In this regard Drs. Simpson, Joneja and Fitzcharles agree. Dr. Fitzcharles summarized the case for not prescribing as follows: “Therefore, before physicians can provide medical recommendation or support for use of herbal cannabis, the minimal standards for pharmacotherapy must be met. At present, these elementary criteria are not fulfilled. In the absence of knowledge of effective dosing or true benefits for herbal cannabis for rheumatic complaints, the risks extrapolated from study of persons with recreational use seem to tip the balance against use. We, therefore, believe that herbal cannabis should not at this time be allowed exceptional status as a therapy, different from other modes of therapy.”
The use of a drug that is minimally effective (yet to be shown) might be justified if it were completely safe and inexpensive. However, there is reason to believe that cannabinoids are not without toxicity, albeit much of the data comes from recreational users. Inhaled cannabis impairs reaction time, selective attention, short-term memory, and motor control for up to five hours following consumption, with increasing effects for increasing doses. This is quite relevant since the proposed uses for medical marijuana all involve chronic conditions. In an American study of over 8,000 adults, marijuana users had a 1.4 times higher incidence of depression than nonusers. Moreover, cannabis is increasingly accepted as an addictive substance, at least in recreational users. In addition, the limited human literature shows that marijuana use increases heart rate, blood pressure and risk of heart attack.
If you would like to see how your opinions match those of colleagues, there is a NEJM interactive case testing the scenario of using these agents in cancer as an antiemetic. A balanced pro and con discussion is followed by over 100 online responses, reflecting a breadth of opinions on these cases.
Of course there is not unanimity amongst physicians. A Dr. Danial Schecter has recently announced plans to open the Cannabinoid Medical Clinic. He has an interesting system of free prescriptions but charges $100-200 for the required counseling for use of the Medicine. I’ll let you be the judge of the ethics of that arrangement. Schecter is quoted as saying “It’s always exciting to be a leader in the field; it’s a great way to help people and it’s also, from a financial perspective, a good business opportunity.” I suspect at least a potion of that assessment is true. Nonetheless, Schecter is not alone and others, such as Terry Roycroft president of Vancouver-based Medicinal Cannabis Resource Centre Inc. (MCRCI) is planning two walk-in clinics in Toronto and has future plans to open clinics in Halifax, Montreal, Calgary and Edmonton.
The demand for marijuana is not manufactured by physicians. Patients themselves are advocates for marijuana. Witness this chat stream I found early in my research for this blog: patients looking for “Marijuana-Friendly Doctors”.
The position of the federal government is nuanced/conflicted. One is no longer required to have a license to grow medical marijuana, you just need a doctor to prescribe it. However, doctors, in general, don’t want to prescribe the drug, except a few who insist on being paid for the prescription. The Harper government appears to favour commercial production of marijuana and to be against individuals growing their own medical marijuana.
If you have 16 minutes, watch 16X9’s assessment of Canada’s Medical Marijuana Program. It is an embarrassing account of patients trying to get medical marijuana and being charged $1000 to have access to medical marijuana.
So, now that patients do not require a license to grow marijuana and are required to get it from their doctor by prescription, the ball has been tossed to Canadian physicians. There are many approaches we could take. As I talked to people about this blog, some suggested that the term ‘medical’, as applied to marijuana, is a red herring. This reflects the viewpoint that the real issue is decriminalization, which would then allow patients to use marijuana as they might use alcohol: purchasing legal amounts at controlled outlets and using it within the guidance of federal and provincial laws. This viewpoint of course does not account for the possibility, yet untested, that unlike alcohol there is some important medical value to properly administered marijuana or its derivatives. Others – lay people – are excited by the economic boom they foresee with this new industry plus they have “heard of the many cures” achieved using marijuana. Clearly this is not an issue that will go away! I suggest we, as a profession, support and lobby for randomized clinical trials in areas such as therapy for arthritis but refrain from prescribing marijuana at present because it is an agent whose chemical composition, benefits and risks we don’t adequately understand.
So what is the answer to the question posed at the beginning of this blog?
a) I can’t its illegal to prescribe marijuana – No it is not illegal to prescribe.
b) I can but I will have to charge $100 for the counseling required for you to understand the use of this effective therapy – Not ethical in my view (and is it legal?)
c) You can just grow it yourself and use it as needed – No longer legal pending appeal.
d) I am not convinced of its benefit and there are no data showing its safety and effectiveness for your condition – This seems like the opinion of the CMA president-elect and is one that I support.
Until there are clarifying data, I suggest that we follow the advice of the US Physician, Dr. Bernard Lown, who said, “Caring without science is well-intentioned kindness, but not medicine.” While we may be tempted to prescribe, there is an inadequate basis for the use of marijuana as a medical therapy for most conditions at present. We owe it to patients to do the studies to clarify the proper use of this drug and establish its proper dosing, safety and efficacy. Our politicians owe more intelligible legislation.