Medicinal cannabis can interact with some prescription medicines, over-the-counter medicines and other substances. This is why patients should tell their doctor, nurse practitioner or medicinal cannabis clinic about everything they currently take before starting treatment.
Why Can Interactions Happen?
Medicinal cannabis products may contain CBD, THC or a combination of both. These compounds can affect the body differently and may change how certain medicines work.
CBD can also affect enzymes in the liver responsible for processing some medicines, potentially changing their levels in the body.
Medicines That May Need Extra Attention
Your healthcare practitioner may need to consider medicinal cannabis carefully if you use medicines such as:
- Blood thinners
- Anti-seizure medicines
- Sedatives or sleeping medicines
- Some antidepressants
- Medicines that cause drowsiness
This does not automatically mean medicinal cannabis cannot be used. Your practitioner may instead recommend closer monitoring, dosage adjustments or a different product.
Alcohol, Drowsiness and Driving
THC can cause drowsiness, dizziness and slower reaction times. Combining it with alcohol or other medicines that cause sedation may increase these effects.
Patients should avoid driving or operating machinery when impaired.
Always Tell Your Prescriber
Before your consultation, prepare a list of your current medicines, supplements and regular treatments.
If your medicines change after starting medicinal cannabis, tell your clinic or healthcare practitioner. Do not stop or change prescribed medicines without professional advice.
Important: This article provides general educational information and is not medical advice. Medicine interactions should be discussed with your doctor, nurse practitioner, pharmacist or other appropriate healthcare professional.
