Cannabinoids in the Management of Acute Pain: A Systematic Review and Meta-analysis

Aaron Gazendam; Nicholas Nucci; Kyle Gouveia; Hassaan Abdel Khalik; Luc Rubinger; Herman Johal

doi:10.1089/can.2019.0079

Cannabinoids in the Management of Acute Pain: A Systematic Review and Meta-analysis

Cannabis Cannabinoid Res. 2020 Dec 15;5(4):290-297. doi: 10.1089/can.2019.0079. eCollection 2020.

Authors

Aaron Gazendam¹, Nicholas Nucci², Kyle Gouveia³, Hassaan Abdel Khalik³, Luc Rubinger¹, Herman Johal^{1

4}

Affiliations

¹ Center for Evidence-Based Orthopaedics, Division of Orthopaedic Surgery, Department of Surgery, McMaster University, Hamilton, Canada.
² Northern Ontario School of Medicine, Lakehead University, Thunder Bay, Canada.
³ Michael G. DeGroote School of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Canada.
⁴ Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Canada.

Abstract

Objective: To synthesize the best evidence surrounding the efficacy of cannabinoids for acute pain in the clinical setting based on subjective pain scores and observed adverse effects. Design: Systematic review with meta-analysis. Data Sources: PubMed, Embase, Cochrane Databases, and Google Scholar. Eligibility Criteria: English-language randomized-controlled clinical trials comparing cannabinoids with placebo in patients with acute pain. Data Extraction and Synthesis: Study quality was assessed using the Cochrane risk of bias tool. All stages were conducted independently by a team of three reviewers. Data were pooled through meta-analysis and stratified by route of administration. Primary Outcomes and Measures: Patient-reported pain and adverse events (AEs). Results: Six trials (678 participants) were included examining oral (5 trials) and intramuscular (1 trial) cannabinoids. Overall, there was a small but statistically significant treatment effect favoring the use of cannabinoids over placebo (-0.90, 95% confidence interval [CI] -1.69 to -0.1, i ²=65%, p=0.03). When stratified by route of administration, intramuscular cannabinoids were found to have a significant reduction in pain relative to placebo (-2.98, 95% CI -4.09 to -1.87, i ²=0%, p<0.0001). No difference in effect was observed between oral cannabinoids and placebo (-0.21, 95% CI -0.64 to 0.22, i ²=3%, p=0.34). Serious AEs were rare, and similar across the cannabinoid (14/374, 3.7%) and placebo groups (8/304, 2.6%). Conclusions: There is low-quality evidence indicating that cannabinoids may be a safe alternative for a small but significant reduction in subjective pain score when treating acute pain, with intramuscular administration resulting in a greater reduction relative to oral. Higher quality, long-term randomized-controlled trials examining whether there may be a role for cannabinoids in treating acute pain are required.

Keywords: acute pain; cannabinoids; meta-analysis; surgical pain; systematic review.

Publication types

Review