A primer on medicinal cannabis safety and potential adverse effects

Aust J Gen Pract. 2021 Jun;50(6):345-350. doi: 10.31128/AJGP-02-21-5845.


Background: Medicinal cannabis prescriptions are on the rise in Australia, and general practitioners will increasingly encounter patients using cannabis-based products.

Objective: The aim of this review is to provide a primer on the safety issues that need to be considered with medicinal cannabis.

Discussion: Medicinal cannabis is generally well tolerated when dosed appropriately. It is important for doctors to consider carefully the Δ9-tetrahydrocannabinol (THC) and/or cannabidiol (CBD) content of the products. CBD is not intoxicating and has fewer safety concerns than THC. When commencing a new medicinal cannabis product, the recommendation is to prescribe relatively low doses and slowly up-titrate the dose. This aims to minimise dose-related toxicities and the potential for drug-drug interactions with concomitant medications. THC found in medicinal cannabis may acutely impair cognitive function and is best not prescribed to children or adolescents unless the benefits outweigh the risks. THC-containing cannabis products should not be prescribed to individuals with angina or a history of myocardial infarction, or to those who have a personal or family history of psychosis.

Publication types

  • Review

MeSH terms

  • Adolescent
  • Cannabidiol* / adverse effects
  • Cannabis* / adverse effects
  • Child
  • Dronabinol / adverse effects
  • Drug-Related Side Effects and Adverse Reactions*
  • Humans
  • Medical Marijuana* / adverse effects


  • Medical Marijuana
  • Cannabidiol
  • Dronabinol