CADTH is committed to supporting Canada’s health care decision-makers through this challenging and uncertain time.
For evidence, tools, and resources related to COVID-19, visit our COVID-19 Evidence Portal.


Begin main content

The Use of Medical Cannabis with Other Medications: A Review of Safety and Guidelines

Last updated: April 19, 2017
Project Number: RC0878-000
Product Line: Rapid Response
Research Type: Drug
Report Type: Summary with Critical Appraisal
Result type: Report


  1. What is the clinical evidence regarding the safety of the use of medical cannabis with other medications?
  2. What are the evidence-based guidelines regarding the interaction of the use of medical cannabis with other medications?

Key Message

Limited data on medical cannabis and drug-drug interactions were obtained from a low quality systematic review. Nabilone may have additive depressant effects with diazepam when taken together with alcohol and codeine, and it may decrease the need for opioids, nonsteroidal anti-inflammatory drugs, tricyclic antidepressants, dexamethasone and ondansetron when used concomitantly. No evidence-based guidelines were identified.