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SafeMedicationUse Newsletter

Cannabis for Medical Purposes—Do You Have the Right Product?


Cannabis contains many different chemicals, including the cannabinoids delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). The effects of cannabis on the body and brain can vary depending on a person's health conditions and medication use, amount of THC and CBD in the cannabis product, and other factors. More information about the health effects of cannabis is available on Health Canada's website.

Many Canadians report using cannabis for medical purposes. Accessing cannabis for medical purposes is different from filling your prescription at a pharmacy. This may include obtaining a medical authorization document from your doctor or nurse practitioner. As with any medication, mistakes (errors) when selecting or using a cannabis product can happen and may result in harmful side effects.

Correct selection and use of an appropriate cannabis product(s) for medical purposes is important to minimize the risk of harm and prevent medication errors. is aware of errors resulting in harm related to:

  • accidentally selecting the wrong cannabis product online
  • delivery of a wrong cannabis product, and
  • use of the wrong cannabis product at home. shares the following tips for minimizing errors when selecting and using cannabis products:

  1. 1. PLAN

    • Talk to your health care practitioner about the use of cannabis for medical purposes.
    • Ask that your medical authorization document includes additional details such as the recommended product form(s) and amount of THC and CBD.
    • Discuss with your health care practitioner how to use the cannabis product(s) properly, including details such as dose and timing of use, especially if you have health conditions or are using other medications. These details are important to help in the decision-making for cannabis for medical purposes, especially for children, older adults, or others who may be more vulnerable to side effects.


    • When selecting cannabis product(s) online or in person, based on discussion with your health care practitioner, verify the following are appropriate for your needs:
      • - product form (e.g., oil)
      • - amounts of THC and CBD in the product
    • Check the label to verify that you received the right product, even if you are re-ordering the same or similar product. Do not rely on the product's appearance. Since all legal cannabis products are required to be in plain packaging and labelling, they may appear similar.

  3. 3. USE

    • When using cannabis products at home, double check the product label to make sure you are using the appropriate product at the right time of day.
    • Follow the instructions for use, including those discussed with your health care practitioner and those available on Health Canada's website.

  4. 4. FOLLOW-UP

    • Speak with your health care practitioner if you have any questions or concerns about the use of cannabis for medical purposes.
    • Follow up if you are not responding to the cannabis product as expected or if you are experiencing any side effects.

Help improve the safety of cannabis products for all Canadians by reporting possible side effects, and cannabis errors.

Medication safety bulletins contribute to Global Patient Safety Alerts

This newsletter was developed in collaboration with Health Canada, Best Medicines Coalition and Patients for Patient Safety Canada.

Recommendations are shared with healthcare providers, through the ISMP Canada Safety Bulletin, so that changes can be made together.

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