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Medical Cannabis

What Patients with Cancer Need to Know

Medical cannabis can help with some of the symptoms and side effects of cancer and cancer treatments. Read the information below to find out more. Talk to your health care team before trying medical cannabis.

Patient handout: Medical Cannabis: What patients with cancer need to know

For more information on medical cannabis, click "+" on the questions below.

  • Medical cannabis, also known as medical marijuana, comes from the flowers, seeds and leaves of the cannabis plant. 
  • Cannabinoids are the chemicals in cannabis that can act as drugs.  
  • The two most familiar cannabinoids are tetrahydrocannabinol (THC) and cannabidiol (CBD). 
  • The amount of THC and CBD in a cannabis product is responsible for most of its effects. 
  • It is important for you to know how much THC and CBD are in the product you are taking. 
  • There is no human clinical trial evidence that cannabinoids have any effect on cancer growth.
  • Pain
  • Nausea: queasy feeling or feeling sick to your stomach
  • Anxiety: a feeling of worry, nervousness, or unease
  • Insomnia: trouble falling asleep or staying asleep
Do not use cannabis if you:

  • Are allergic to cannabis
  • Have a history of psychosis
  • Are pregnant
  • Have a heart condition such as unstable angina or a recent heart attack
It is important that you speak with your health care team to see if cannabis is right for you.
  • Extracts: this is the best form for cancer patients.  It absorbs quickly in your mouth and does not have a strong smell.
  • Edibles (products you eat or swallow): cookies, teas, capsules or tinctures (drops).
  • Suppositories that you insert into your rectum (bum).  
  • We do not recommend inhaling (smoking or vaping) cannabis. The smoke or gas may damage your lungs.

Side effects of THC can include:

  • Dry mouth
  • Slower reaction time
  • Hunger
  • Relaxation
  • Euphoria: feeling very happy or excited
  • Sleepiness
  • Sensitivity to colour and sound
CBD does not usually cause these side effects.

There are no known long-term side effects from using cannabis extracts.

Do not drive for at least 4 hours, if you take an extract under the tongue with high levels of THC. Do not drive for at least 6 hours if you swallow it.
Talk to your health care team before using cannabis.

It is best to start with a very small amount and then increase it slowly.

If you use cannabis extract, it will take 30-90 minutes for it to work. It can take 2-3 hours for maximum effect. Wait 3-4 hours before taking another dose.  It can take up to 8 hours for the effects to wear off. 

You are unlikely to get addicted to cannabis if you are using it for a health reason.

Cannabis may interact with some medications. Check with your oncologist or pharmacist before using cannabis.

The Supreme Court of Canada has ruled that patients can use cannabis for medical reasons. 

  1. You can get a prescription from your doctor for a synthetic cannabinoid medicine (nabilone) or a plant-based product (Nabiximols). Synthetic cannabinoids are human-made chemicals that act like THC in your body.  These medicines are expensive but may be covered by extended health plans. You can fill the prescription at a regular pharmacy. 
  2. You can get plant-derived cannabis products from a list of approved licensed producers (LP). The list can be found here. When you look at the LP websites, search for an extract that has equal amounts of THC and CBD, or less THC than CBD if you have never tried medical cannabis before.
    Each LP has a specific form that you must fill out. There is a different form for you to give to your doctor. The LP will mail the product you order to your home.
BC Cancer does not recommend getting cannabis from dispensaries or using cannabis that was grown in someone’s home.

  • Storefront cannabis dispensaries are either illegal or only licensed for recreational use.  The quality of the cannabis from unlicensed dispensaries is not controlled. 
  • It is legal to get cannabis from a person authorized to grow cannabis at home. But the quality of this cannabis is not consistent.
  • Note: The video asks you to type in "oils" when searching for licensed producers.  This has changed. Please type in "extracts".  Our video will be updated soon.‎

The only way to know if a product is from a Canadian Licensed Producer is the excise stamp. Each province has a different coloured excise stamp.  Here is B.C's stamp:

For more information, check out the Health Canada webpage about Cannabis Product Labels 

Nabilone and Nabiximols are expensive and not covered by Pharmacare or other provincial drug plans. Some extended health plans will cover them.

You may be able to claim the cost of products bought from a Licensed Producer on your tax return.
You can travel within Canada with cannabis as long as you have the original packaging from your licensed producer or a letter from your doctor. 

You cannot take products with cannabis to another country. It is illegal. has a lot of good information if you want to learn more about medical cannabis.

Health Canada has very detailed information about medical cannabis.

recommended websites, books, and handouts about medical cannabis and cancer.

BC Cancer has opened a medical cannabis clinical trial called CAFCARS: Cannabis For Cancer-Related Symptoms.

For more information, go to the CAFCARS website.‎

SOURCE: Medical Cannabis ( )
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