Advice to the Profession

The College of Physicians & Surgeons of Alberta (CPSA) provides advice to the profession to support physicians in implementing the CPSA Standards of Practice. This advice does not define a standard of practice, nor should it be interpreted as legal advice.

Marihuana for Medical Purposes

Published: June 4, 2014
Revised: October 25, 2016
Related standard of practice: Marihuana* for Medical Purposes

Please note: The College has chosen to spell “Marihuana” with an “h” (alternative spelling “marijuana”) to align with Health Canada’s Controlled Drugs and Substances Act.

What physicians need to know

 Patient Medical Document

Physicians must stay current on necessary clinical knowledge, provide treatments they believe are in the best interest of their patients, and engage in meaningful discussions with their patients about the care that is being provided. Completing a medical document for use of marihuana is no different. Physicians who choose to complete a medical document authorizing the use of marihuana must not charge a fee for doing so, as this is considered comparable to writing a prescription as an insured service.

The College notifies physicians when they are registered to complete medical documents authorizing marihuana for medical purposes. Physicians are free to complete a medical document on receipt of notification.

Health Canada regulations require physicians to provide specific information contained in a medical document. A sample Patient Medical Document with the required information is available.

  • The CPSA requires physicians to send a copy of the medical document to the College within one week of completing the medical document by Mail: c/o College of Physicians & Surgeons of Alberta, #2700, 10020 – 100 Street NW, Edmonton, AB T5J 0N3; or Fax: 780-429-1981, Attention: Physician Prescribing Practices
  • Health Canada regulations allow patients to obtain a maximum of 1 month’s supply at a time (30 times the daily quantity) to a maximum of 150 grams per month. Physicians may choose to allow smaller amounts in shorter intervals.
    Heath Canada regulations allow a single medical document to authorize use for 1 year but physicians may choose to authorize for a shorter duration.
Patients with a history of substance use disorder or other addictions may be at risk of misusing marihuana for medical purposes. Understanding this risk, discussing this risk with your patient, and instituting appropriate safety precautions if you feel marihuana may be helpful to your patient, is essential. The following addiction risk instruments are available:

The Drug Abuse Screening Test (DAST)
Opioid Risk Tool
CAGE Questionnaire

The elements of informed consent include a fulsome discussion of risks and benefits of any proposed course of action. Refer to the Informed Consent standard of practice  and Code of Ethics. At a minimum, the following should be discussed with the patient:

A.  Potential benefits, including a discussion of the paucity of good evidence for effectiveness and safety.
B.  Potential risks, including the following:

  • Precipitation of psychotic symptoms, especially if there is a family history of psychotic illness.
  • Impairment to lung function from marihuana smoke inhalation, including risk of cancer and obstructive lung disease. There is contradictory evidence in the literature about these risks.
  • Impairment in cognitive function that may impact fitness to engage in activities and/or responsibilities.
    • Marihuana can impair cognition so patients must be warned of this effect and that use can impair the ability to drive or operate equipment. Patients should be advised to neither drive, nor operate equipment while under the influence of marihuana. Evidence for diminution of the effects of marihuana on ability to drive is limited.
  • Impacts on safety-sensitive occupations, potentially necessitating work restrictions or limitations.
    • Physicians should ask about job tasks and counsel patients using marihuana for medical purposes about workplace safety concerns. Individuals who serve in positions where public safety is a factor (e.g., railway and aviation industries) may not be able to continue in their occupation while using marihuana. Physicians should notify the relevant regulatory authority when appropriate. Refer to Legislated Reporting and Release of Medical Information
  • Impact on insurance or benefits coverage, including the patient’s existing life, disability and automobile insurance policies. Patients should be advised to check with their insurance policy holder.
  • Unauthorized access to marihuana. Patients must be advised to store their marihuana in a secure manner in order to prevent others accessing it or stealing it.

Marihuana does not have a drug information number and will not be dispensed by pharmacists. As such, it cannot be entered into PIN so there will be no record of a patients use in PIN. The TPP profile will contain a note about a patient’s use of marihuana for medical purposes because physicians must provide a copy of the medical document to the College. Physicians need to be aware of other medications being prescribed that may potentially interact with marihuana in order to minimize the risk of harm.

Under Health Canada’s revised Access to Cannabis for Medical Purposes Regulations (ACMPR), patients may grow cannabis for their personal use based on authorization from their physician. The patient then submits the authorization directly to Health Canada rather than the physician submitting the authorization to the licensed producer.

The frequency of evaluation of patients should be determined by the clinical need and should be more frequent when a patient initiates use. Once a patient is using a stable amount of marihuana to derive benefit they must be evaluated in person at least every three months.

A variety of strategies can be used and may include the following:

  • treatment agreements that ensure only one physician complete the medical document and only one licensed producer be used
  • careful documentation of amount of marihuana used. Watch for rapidly escalating use or running out of marihuana early
  • clinical assessment of benefits and risk
  • compliance to your recommendations with respect to driving, etc.
The Health Canada document Information for Health Professionals states that cannabis should not be used in patients:

  • under the age of 18
  • with severe cardiopulmonary disease
  • with respiratory insufficiency (asthma, COPD)
  • with severe liver or renal disease
  • with a personal history of psychiatric disorders (especially schizophrenia), or a family history of schizophrenia
  • with mania or depression (these patients should be under careful psychiatric monitoring)
  • who are pregnant or breastfeeding
  • with a history of substance abuse, including alcohol abuse, or concomitant use of psychoactive drugs