Under Canada’s Access to Cannabis for Medical Purposes Regulations (ACMPR), physicians or nurse practitioners have the authority to write was has been broadly described as “prescriptions” for medical cannabis. But in fact, these are not prescriptions in the traditional sense.

A prescription, for example, must include the brand and/or generic name of the drug, the dose in appropriate dosage units (e.g., 100 mg), route of administration (e.g., “by mouth”), and frequency of dosing (e.g., “three times a day”). If the intention is that a drug is to be taken “as needed” (PRN), the prescriber must provide guidance on how frequently it can be taken, the maximum daily dose and the criteria for taking it (e.g., “for severe pain”).

In other words, when a clinician writes a prescription he or she has a clear understanding of exactly what the patient will receive, how it will be administered, how strong it is, and how much and how frequently it will be taken. If there are questions, prescribers can turn to online and print references, such as the medication’s Drug Product Monograph posted by Health Canada. A Drug Product Monograph is a factual scientific document that, devoid of promotional material, describes the properties, claims, indications and contraindications and action of the agent, as well as any other information required for its optimal, safe and effective use.1

In 2014, when the current access program was launched, Health Canada produced a document to provide information on medical cannabis for healthcare professionals. Health Canada stressed that this document was only a summary of the literature concerning potential therapeutic uses and harmful effects and did not have the type or level of information contained in a Drug Product Monograph.2

The process of recommending medical cannabis differs in several significant ways from prescribing a pharmaceutical. In all provinces, the healthcare professional doesn’t write a prescription to be filled at a pharmacy but completes a Health Canada form recommending the patient be enrolled into the medical cannabis program. Acceptance into the program means the patient can register as a client with a licensed cannabis producer.

On the form, the healthcare provider must specify:

  • Date on which the document is made
  • Name, surname and date of birth of the patient
  • Name and surname of the physician or nurse practitioner authorizing the order
  • Shipping address specified in the patient’s registration document
  • Quantity in grams for a thirty-day supply of dried cannabis – up to five grams of dried cannabis can be recommended per patient per day (which for 30 days comes to 150 grams, the most a person can have without violating the possession laws) but the College of Family Physicians of Canada suggests the upper safe level should be three grams a day3 (In fact, as of May, 2017, Veterans Affairs reduced the cap for reimbursing veterans authorized to take medical cannabis from ten to three grams a day4).
  • Optionally, name (e.g., strain) of the medical cannabis being ordered

Different strains of cannabis are bred by producers to have different concentrations of THC (delta-tetra-hydrocannabinol, the compound that is mainly responsible for cannabis’ psychoactive effects) and different ratios of THC to CBD (cannabidiol, a cannabinoid that does not appear to have intoxicating effects but may have anti-inflammatory and other helpful effects. Specifying the strain may help to define the concentration of THC and the THC to CBD ratio but requires knowledge about the nature of individual strains. Complicating the situation is the fact that names of strains can vary between producers.

Finally, even if a strain is specified by the healthcare provider, producers have the authority to substitute a similar one if the one named is not available. To get around this issue, the College of Family Physicians of Canada recommends that physicians should specify the THC concentration (e.g., 9% or less THC) and instruct producers to send information on the THC percentage directly to the physician’s office.3 3 As well, although the recommendation is made for an amount of dried cannabis, the product the patient receives may be dried, fresh or an oil as producers use formulas to convert from dried to other forms.56 Fundamentally, “prescriptions” for medicinal cannabis are authorizations for access, not a precise identification of a controlled medication that is prepared and dispensed by a trained pharmacist. They are more like permission slips with non-binding recommendations than actual prescriptions for medications.

Given these factors, it’s not hard to see why many clinicians – and patients – are anxious for more and better information about not only the pros and cons of medical cannabis but how to prescribe and use it. The Michael G. DeGroote Centre for Medicinal Cannabis Research was created to develop, curate, and make accessible this sort of information. We at the Centre hope you will take advantage of all the resources this site offers.  


Author Details

The latest scientific evidence on this topic was reviewed by the Centre's leadership team. This evidence brief is written by Corinne Hodgson, DHealth, assessed for accuracy by Medical Advisor Dr. Ramesh Zacharias, MD, a clinician with expertise in chronic pain. There are no conflicts of interest. Questions regarding this piece should be directed to Dr. Ramesh Zacharias (zacharias@hhsc.ca).


References
  1. Health Canada. Frequently Asked Questions: Product Monographs Posted to the Health Canada Website. Date: 2014-07-11. https://www.canada.ca/en/health-canada/services/drugs-health-products/drug-products/applications-submissions/guidance-documents/product-monograph/frequently-asked-questions-product-monographs-posted-health-canada-website.html
  2. Health Canada. Information for Health Care Professionals, Cannabis (marihuana, marijuana) and the cannabinoids. Latest version: February 2013. https://www.canada.ca/en/health-canada/services/drugs-health-products/medical-use-marijuana/information-medical-practitioners/information-health-care-professionals-cannabis-marihuana-marijuana-cannabinoids.html
  3. College of Family Physicians of Canada. Authorizing Dried Cannabis for Chronic Pain or Anxiety, Preliminary Guidance, September 2014. https://www.cfpc.ca/uploadedFiles/Resources/_PDFs/Authorizing%20Dried%20Cannabis%20for%20Chronic%20Pain%20or%20Anxiety.pdf
  4. Wood A. Ottawa places three-gram limit on medical pot coverage for veterans. The Globe and Mail, November 22, 2016. https://beta.theglobeandmail.com/news/politics/ottawa-places-three-gram-limit-on-amount-of-medical-pot-it-covers-for-veterans/article32976065/?ref=http://www.theglobeandmail.com&
  5. Medical marijuana: Considerations for Canadian doctors. Canadian Medical Protection Association. Revised August 2016. https://www.cmpa-acpm.ca/en/advice-publications/browse-articles/2014/medical-marijuana-new-regulations-new-college-guidance-for-canadian-doctors
  6. College of Physicians and Surgeons of Ontario. Policy Statement #8-16. Marijuana for Medical Purposes. http://www.cpso.on.ca/CPSO/media/documents/Policies/Policy-Items/Marijuana-for-Medical-Purposes.pdf?ext=.pdf