Cannabis and medication: lots of questions, not many answers

While cannabis consumption is now legal in Canada, it’s not entirely without consequences, particularly for people with health problems or who take medication.

Cannabis and diseases

Cannabis creates a number of effects on the body that can aggravate diseases or interact with their treatment. For example, cannabis is known to increase blood pressure, and it increases and can alter heartrate too. It is therefore recommended that people with heart problems avoid consuming cannabis.

People with lung problems like asthma should avoid smoking cannabis. Cannabis smoke is just as dangerous to your health as cigarette smoke as it also contains several substances that are potentially harmful.

From a medical standpoint, cannabis can be prescribed to treat various health problems, including nausea in cancer patients, certain types of refractory pain, and spasticity caused by multiple sclerosis.

Even if you believe cannabis could be an option for you, don’t play doctor by self-prescribing cannabis. Only a doctor who clearly understands the indications for cannabis can assess your specific needs based on your health, and can determine whether cannabis is a safe option for you.

Cannabis and medication

Avoid consuming cannabis together with medicines that slow down the nervous system, like sleeping pills, narcotic analgesics, or certain allergy medication, as the effects of the two substances can be cumulative. 

Cannabis interacts with a number of other types of medications, including the following: 

• Antiretroviral drugs for the treatment of HIV
• Certain antidepressants
• Certain antibiotics or antifungal treatments
• Certain medicines for heartburn
• Certain heart medication 

Cannabis can also interact with certain natural health products, including St. John's wort (hypericum perforatum). 

Team up with your pharmacist and doctor

If you suffer from a chronic disease or are taking medication, it is important that you advise your doctor and pharmacist if you consume cannabis. They can help determine whether your cannabis consumption can have an impact on your condition or your treatment.