Education/Professional Associations:

Department of Medicine, Faculty of Medicine, Division of Community Internal Medicine, University of British Columbia (UBC)

Department of Medicine, Faculty of Medicine, Division of Palliative Care, UBC

Faculty of Pharmaceutical Sciences, UBC



Dr. Caroline MacCallum is a specialist in internal medicine, with expertise in complex pain and cannabinoid medicine. She is a clinical instructor in the Department of Medicine; Adjunct Professor in the Faculty of Pharmaceutical Sciences program; and associate member in the Dept. of Palliative Care at the University of British Columbia.

Dr. MacCallum is assistant editor for the recently published Cannabinoids and Pain book by Springer; and first author on eight chapters pertaining to pharmacovigilance including: mental health, impairment, dosing, patient safety (contraindications & drug interactions), use in adolescence, product safety, pain, and opioid substitution.

Her foremost contribution to the scientific literature is Practical Considerations for Medical Cannabis Administration and Dosingpublished in the European Journal of Internal Medicine. This seminal paper has been cited over 300 times.

Dr. MacCallum has presented internationally on the topics of cannabis dosing, safety and polypharmacy reduction/substitution. Her research interests focus on the use of cannabis as an adjuvant to standard of care for complex conditions including: chronic pain, fibromyalgia/chronic fatigue syndrome, neurodevelopmental disorders, post-traumatic stress disorder, and traumatic brain injury; deprescribing/drug substitution; pharmacovigilance and impairment.

Presentation Abstract

Endocannabinoids for Pain, Sleep, and Deprescribing Opioids

Cannabinoids have multimodal mechanisms of action producing analgesia and may also provide relief for symptom clusters which accompany chronic non-cancer pain via effects on the endocannabinoid system.

The evidence from existing clinical studies provides important preliminary data to show that there may be synergistic effects between cannabinoids and opioids (cannabis-opioid mutual potentiation) wherein cannabinoids interact and sensitize opioid receptors in anti-nociceptive brain regions. An adjunct trial of cannabis with opioid therapy in individuals with chronic non-cancer pain has been proposed for symptom improvement, and potential opioid tapering, through these synergistic effects.

Studies have demonstrated benefits for cannabis in the management of insomnia through improvements in sleep quality and sleep disturbances. Data on the effects of cannabinoids on sleep in medical conditions such as chronic pain and PTSD are also reviewed.

This presentation will review the available evidence and summarize practical steps for initiating the safe use of medical cannabis in patients with chronic pain, insomnia, and for those who wish to discontinue opioid use.


Peer Reviewer. Ask Your Provider About Cannabis: Increasing Nurse Practitioner Knowledge and Confidence. Cannabis and Cannabinoid Research. 2021 –

Peer Reviewer. Perspectives of pediatric oncologists and palliative care physicians on the therapeutic use of cannabis in children with cancer. Cancer Rep (Hoboken). 2021 –

Rapid response to ‘Medical cannabis or cannabinoids for chronic pain: a clinical practice guideline’. BMJ. 2021 –

Narouze SN, MacCallum CA. eds. Cannabinoids and Pain. Springer; 2021

Consensus recommendations on dosing and administration of medical cannabis to treat chronic pain: results of a modified Delphi process. Journal of Cannabis Research. 2021 –

Is medical cannabis safe for my patients?” A practical review of cannabis safety considerations. European Journal of Internal Medicine. 2021 –

Practical strategies using medical cannabis to reduce harms associated with long term opioid use in chronic pain. Frontiers in Pharmacology. 2021 –

Duration of neurocognitive impairment with medical cannabis use: a scoping review. Frontiers in Psychiatry. 2021 –

Guidance in Authorizing Cannabis Products Within Primary Care © 2021 The College of Family Physicians of Canada

Canadian clinical practice guidelines for the use of plant-based cannabis and cannabinoid-based products in the management of chronic non-cancer pain and co-occurring conditions: protocol for a systematic literature review. BMJ Open. 2020;10:e036114 –

Characterization of mental health in cannabis dispensary users, using structured clinical interviews and standardized assessment instruments. BMC Psychiatry. 2019;19:335 –

Practical considerations in medical cannabis administration and dosing. European Journal of Internal Medicine. 2018;49 –