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

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 (À0.90, 95% confidence interval [CI] À1.69 toÀ0.1, 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 (À2.98, 95% CIÀ4.09 toÀ1.87, i 2 = 0%, p < 0.0001). No difference in effect was observed between oral cannabinoids and placebo (À0.21, 95% CI À0.64 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.

Cannabinoid Formulations and Delivery Systems: Current and Future Options to Treat Pain

“…Selecting studies focused on acute pain, Gazendam has analysed six oral administration trials, mainly, of THC. This analysis revealed that there was a small, but significant, reduction in subjective pain scores compared with placebo in patients experiencing acute pain [ 274 ].…”

Cannabis, cannabinoids, and cannabis-based medicines: future research directions for analgesia

“…Current evidence of the effectiveness of cannabinoids for acute pain states is poor 11. This is partially due to lack of satisfactory studies rather than a surfeit of negative studies.…”

Cannabinoid Receptors: An Update on Cell Signaling, Pathophysiological Roles and Therapeutic Opportunities in Neurological, Cardiovascular, and Inflammatory Diseases

“…The role of central CB1R, and both central and peripheral CB2R inducing anti-nociceptive actions in neuropathic and inflammatory models of pain has been described in earlier ( Section 3.2.2 and Section 3.2.3 ). Additionally, recently conducted retrospective and meta-analysis revealed the utility of cannabinoids in the treatment of postoperative pain and other forms of acute pain states [ 589 , 590 ]. Interestingly, the peripheral CB1R has also been implicated in inducing anti-nociception and resolving associated inflammatory states in various animal models of pain [ 591 , 592 , 593 , 594 ].…”