The Canadian Medical Association (CMA) has always recognized the unique requirements of those individuals suffering from a terminal illness or chronic disease for which conventional therapies have not been effective and for whom cannabis may provide relief.
However, there are a number of concerns, primarily related to the limited evidence to support many of the therapeutic claims made regarding cannabis for medical purposes, and the need to support health practitioners in their practice.1,2,3,4
While the indications for using cannabis to treat some conditions have been well studied, less
information is available about many potential medical uses.
Physicians who wish to authorize the use of cannabis for patients in their practices should consult relevant CMPA policy5 and guidelines developed by the provincial and territorial medical regulatory authorities to ensure appropriate medico-legal protection. The CMA’s policy Authorizing Marijuana for Medical Purposes6, as well as the CMA’s Guidelines For Physicians In Interactions With Industry7 should also be consulted.
The CMA makes the following recommendations:
1. Increase support for the advancement of scientific knowledge about the medical use of cannabis. The CMA encourages the government to support rigorous scientific research into the efficacy for therapeutic claims, safety, dose-response relationships, potential interactions and the most effective routes of delivery, and in various populations.
2. Apply the same regulatory oversight and evidence standards to cannabis as to pharmaceutical products under the Food and Drug Act, designed to protect the public by the assessment for safety and efficacy.
3. Increase support for physicians on the use of cannabis for medical purposes in their practice settings. As such, CMA calls on the government to work with the CMA, The College of Family Physicians of Canada, the Royal College of Physicians and Surgeons,
and other relevant stakeholders, to develop unbiased, accredited education options and licensing programs for physicians who authorize the use of cannabis for their patients based on the best available evidence.
In 2001, Health Canada enacted the Marihuana Medical Access Regulations (MMAR). These were in response to an Ontario Court of Appeal finding that banning cannabis for medicinal purposes violated the Charter of Rights and Freedoms.8 The MMAR, as enacted, was designed to establish a framework to allow legal access to cannabis, then an illegal drug, for the relief of pain, nausea and other symptoms by people suffering from serious illness where conventional treatments had failed.
While recognizing the needs of those suffering from terminal illness or chronic disease, CMA raised strong objections to the proposed regulations. There were concerns about the lack of evidence on the risks and benefits associated with the use of cannabis. This made it difficult for physicians to advise their patients appropriately and manage doses or potential side effects. The CMA believes that physicians should not be put in the untenable position of gatekeepers for a proposed medical intervention that has not undergone established regulatory review processes as required for all prescription medicines.
Additionally, there were concerns about medico-legal liability, and the Canadian Medical Protective Association (CMPA), encouraged those physicians that were uncomfortable with the regulations to refrain from authorizing cannabis to patients.
Various revisions were made to the MMAR, and then these were substituted by the Marihuana for Medical Purposes Regulations (MMPR) in 2013/ 2014 and subsequently by the Access to Cannabis for Medical Purposes Regulations (ACMPR) in 2016 and now as part of the Cannabis Act (Section 14)9. Healthcare practitioners that wish to authorize cannabis for their patients are required to sign a medical document, indicating the daily quantity of dried cannabis, expressed in grams.
For the most part, these revisions have been in response to decisions from various court decisions across the country.10,11,12 Courts have consistently sided with patients’ rights to relieve symptoms of terminal disease or certain chronic conditions, despite the limited data on the effectiveness of cannabis. Courts have not addressed the ethical position in which physicians are placed as a result of becoming the gate keeper for access to a medication without adequate evidence.
The CMA participated in many Health Canada consultations with stakeholders as well as scientific advisory committees and continued to express the concerns of the physician community. As previously noted, the Federal government has been constrained by the decisions of Canadian courts.
The current state of evidence regarding harms of cannabis use is also limited but points to some serious concerns. Ongoing research has shown that regular cannabis use during brain development (up to approximately 25 years old) is linked to an increased risk of mental health disorders including depression, anxiety, and schizophrenia, especially if there is a personal or family history of mental illness. Long term use has also been associated with issues of attention, impulse control and emotional regulation. Smoking of cannabis also has pulmonary consequences such as chronic bronchitis. It is also linked to poorer pregnancy outcomes. Physicians are also concerned with dependence, which occurs in up to 10% of regular users. From a public and personal safety standpoint, cannabis can impact judgement and increases the risk of accidents (e.g. motor vehicle incidents). For many individuals, cannabis use is not without adverse consequences.3,13,14
Pharmaceutically prepared alternative options, often administered orally, are also available and regulated in Canada.15 These drugs mimic the action of delta-9-tetra-hydrocannabional (THC) and other cannabinoids and have undergone clinical trials to demonstrate safety and effectiveness and have been approved for use through the Food and Drug Act. Of note is that in this format, the toxic by-products of smoked marijuana are avoided.16 However, the need for more research is evident.
Approved by the CMA Board in December 2010.
Last reviewed and approved by the CMA Board in March 2019.
1 Allan GM, Ramji J, Perry D, et al. Simplified guideline for prescribing medical cannabinoids in primary care. Canadian Family Physician, 2018;64(2):111-120. Available: http://www.cfp.ca/content/cfp/64/2/111.full.pdf (accessed 2019 Jan 8).
2 College of Family Physicians of Canada (CFPC). Authorizing Dried Cannabis for Chronic Pain or Anxiety: Preliminary Guidance. Mississauga: CFPC; 2014. Available: https://www.cfpc.ca/uploadedFiles/Resources/_PDFs/Authorizing%20Dried%20Cannabis%20for%20Chronic%20Pain%20or%20Anxiety.pdf (accessed 2019 Jan 8).
3 The National Academies of Sciences, Engineering and Medicine. The health effects of cannabis and cannabinoids: the current state of evidence and recommendations for research. Washington, DC: National Academies Press; 2017. 4 Whiting PF, Wolff RF, Deshpande S, et al. Cannabinoids for medical use: a systematic review and meta-analysis. JAMA 2015;313(24):2456-73.
5 Canadian Medical Protective Association (CMPA). Medical marijuana: considerations for Canadian doctors. Ottawa: CMPA; 2018. Available: https://www.cmpa-acpm.ca/en/advice-publications/browse-articles/2014/medical-marijuana-new-regulations-new-college-guidance-for-canadian-doctors (accessed 2019 Jan 8).
6 Canadian Medical Association (CMA). Authorizing marijuana for medical purposes. Ottawa: CMA; 2014. Available: https://policybase.cma.ca/en/permalink/policy11514 http://policybase.cma.ca/dbtw-wpd/Policypdf/PD15-04.pdf (accessed 2019 Jan 8).
7 Canadian Medical Association. (CMA) Guidelines for Physicians In Interactions With Industry. Ottawa: CMA; 2007. Available: http://policybase.cma.ca/dbtw-wpd/Policypdf/PD08-01.pdf. (accessed 2019 Jan22).
8 R. v. Parker, 2000 CanLII 5762 (ON CA). Available: http://canlii.ca/t/1fb95 (accessed 2019 Jan 8).
9 Cannabis Act. Access to Cannabis for Medical Purposes. Section 14. 2018. Available: https://laws-lois.justice.gc.ca/eng/regulations/SOR-2018-144/page-28.html#h-81 (accessed 2019 Jan 8).
10 Hitzig v. Canada, 2003 CanLII 3451 (ON SC). Available: http://canlii.ca/t/1c9jd (accessed 2019 Jan 8).
11 Allard v. Canada,  3 FCR 303, 2016 FC 236 (CanLII), Available: http://canlii.ca/t/gngc5 (accessed 2019 Jan 8).
12 R. v. Smith, 2014 ONCJ 133 (CanLII). Available: http://canlii.ca/t/g68gk (accessed 2019 Jan 8). 13 Volkow ND, Baler RD, Compton WM, Weiss SRB. Adverse health effects of marijuana use. N Engl J Med. 2014;370(23):2219–2227.
14 World Health Organization. The health and social effects of nonmedical cannabis use. Geneva: World Health Organization; 2016. Available: https://www.who.int/substance_abuse/publications/msbcannabis.pdf (accessed 2019 Jan 8).
15 Ware MA. Is there a role for marijuana in medical practice? Can Fam Physician 2006;52(12):1531-1533. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1952544/pdf/0530022a.pdf (accessed 2019 Jan 8).
16 Engels FK, de Jong FA, Mathijssen RHJ, et.al. Medicinal cannabis in oncology. Eur J Cancer. 2007;43(18):2638-2644. Available: https://www.clinicalkey.com/service/content/pdf/watermarked/1-s2.0-S0959804907007368.pdf?locale=en_US (accessed 2019 Jan 8).