- Adding cannabinoids, including cannabis, to opioids does not significantly reduce cancer pain, conclude the authors of this meta-analysis of 5 randomized controlled trials (RCTs) with more than 1400 patients.
- The addition of cannabinoids was tied to more adverse events (AEs).
Why this matters
- Although studies suggest that many patients with cancer use cannabinoids for pain relief, WHO guidelines note that evidence is lacking for their effectiveness in cancer pain management.
- Systematic review and meta-analysis (narrative analysis: 6 RCTs, n=1460; meta-analysis, 5 RCTs, n=1442).
- Primary outcome: absolute change in mean pain intensity in patients with advanced cancer.
- Funding: None disclosed.
- Cannabinoids vs placebo group showed no difference in the change in average Numeric Rating Scale pain scores:
- Mean difference (MD), −0.21 (P=.14).
- Including only phase 3 studies showed no benefit from cannabinoid use vs placebo:
- MD, −0.02 (P=.80).
- Cannabinoid group had higher odds (ORs) for:
- Dizziness: 1.58 (P=.05).
- Somnolence: 2.69 (P<.001>
- Cannabinoid group showed higher odds (ORs; not significant) for nausea (1.41; P=.08) and vomiting (1.34; P=.21).
- No treatment-related deaths were reported in any study.
- Inconsistencies among studies.
- Self-reported pain scores.
Coauthored with Chitra Ravi, MPharm