Meta-Analysis of 30 Trials Found Cannabinoids More Effective Than Standard Anti-Nausea Drugs for Chemotherapy
Across 30 randomized trials and over 1,100 patients, cannabinoid medications outperformed conventional anti-nausea drugs for chemotherapy-induced vomiting, and patients overwhelmingly preferred cannabinoids.
Quick Facts
What This Study Found
This systematic review and meta-analysis examined 30 randomized clinical trials from over 12,000 initially identified papers, comparing cannabinoids to conventional anti-emetics and placebo for chemotherapy-induced nausea and vomiting.
Five meta-analyses were conducted. Dronabinol significantly outperformed neuroleptic anti-emetics (RR=0.67, NNT=3.4), meaning only 3-4 patients needed treatment with dronabinol instead of neuroleptics for one additional patient to benefit. Dronabinol versus placebo showed a trend favoring dronabinol (RR=0.47) but didn't reach significance.
Nabilone and levonantradol showed similar but non-significant trends against neuroleptics.
The most striking finding was patient preference: across 1,138 patients, the preference for cannabinoids over other drugs was overwhelming (RR=0.33, NNT=1.8), meaning nearly every other patient preferred the cannabinoid.
However, adverse effects were more frequent and intense with cannabinoids than conventional drugs.
Key Numbers
30 RCTs from 12,749 papers. Dronabinol vs. neuroleptics: RR=0.67, NNT=3.4. Patient preference for cannabinoids: RR=0.33, NNT=1.8 (n=1,138). Adverse effects more common with cannabinoids.
How They Did This
Systematic review of PUBMED, EMBASE, PSYCINFO, LILACS, and Cochrane databases through December 2006. From 12,749 papers, 30 randomized clinical trials met inclusion criteria. Five meta-analyses were performed using relative risk and number needed to treat.
Why This Research Matters
This was one of the most comprehensive meta-analyses of cannabinoids for chemotherapy nausea at the time. The clear superiority over neuroleptic anti-emetics and overwhelming patient preference provided strong evidence for cannabinoids in this indication.
The Bigger Picture
This meta-analysis strengthened the evidence base for FDA-approved indications of dronabinol and nabilone for chemotherapy-induced nausea. However, it's worth noting that the comparator drugs (neuroleptics) are not the modern standard of care. Newer anti-emetics (5-HT3 antagonists like ondansetron) had already changed the landscape.
What This Study Doesn't Tell Us
Many included trials were from the 1980s-1990s and used outdated comparator drugs (neuroleptics rather than modern anti-emetics like ondansetron). Some individual trials had small samples. The increased adverse effects of cannabinoids are clinically significant. Publication bias may favor positive results.
Questions This Raises
- ?How do cannabinoids compare to modern 5-HT3 antagonists like ondansetron?
- ?Could cannabinoids add benefit when used alongside modern anti-emetics?
- ?Does patient preference reflect true efficacy or the psychoactive effects?
Trust & Context
- Key Stat:
- NNT of 3.4: treat 3-4 patients with dronabinol for 1 additional to benefit vs. standard drugs
- Evidence Grade:
- This is a systematic review and meta-analysis of 30 RCTs, the strongest form of evidence. However, the comparator drugs are largely outdated, limiting contemporary relevance.
- Study Age:
- Published in 2008. Modern anti-emetics (5-HT3 antagonists, NK1 antagonists) have changed the standard of care since many included trials were conducted. Cannabinoids are now typically used as adjunct or rescue therapy.
- Original Title:
- Therapeutic use of Cannabis sativa on chemotherapy-induced nausea and vomiting among cancer patients: systematic review and meta-analysis.
- Published In:
- European journal of cancer care, 17(5), 431-43 (2008)
- Authors:
- Machado Rocha, F C, Stéfano, S C, De Cássia Haiek, R, Rosa Oliveira, L M Q, Da Silveira, D X
- Database ID:
- RTHC-00318
Evidence Hierarchy
Combines results from multiple studies to find an overall pattern.
What do these levels mean? →Frequently Asked Questions
Are cannabinoids the best anti-nausea option for chemo?
This meta-analysis showed cannabinoids outperformed older anti-nausea drugs. However, modern anti-emetics (like ondansetron) are very effective and weren't the main comparators in these trials. Today, cannabinoids are typically used when modern drugs aren't sufficient.
Why do patients prefer cannabinoids despite more side effects?
Patient preference may reflect better nausea control, the anxiolytic or appetite-stimulating effects, or the psychoactive experience. The overwhelming preference (NNT=1.8) suggests patients valued the overall experience despite the side effects.
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Cite This Study
https://rethinkthc.com/research/RTHC-00318APA
Machado Rocha, F C; Stéfano, S C; De Cássia Haiek, R; Rosa Oliveira, L M Q; Da Silveira, D X. (2008). Therapeutic use of Cannabis sativa on chemotherapy-induced nausea and vomiting among cancer patients: systematic review and meta-analysis.. European journal of cancer care, 17(5), 431-43. https://doi.org/10.1111/j.1365-2354.2008.00917.x
MLA
Machado Rocha, F C, et al. "Therapeutic use of Cannabis sativa on chemotherapy-induced nausea and vomiting among cancer patients: systematic review and meta-analysis.." European journal of cancer care, 2008. https://doi.org/10.1111/j.1365-2354.2008.00917.x
RethinkTHC
RethinkTHC Research Database. "Therapeutic use of Cannabis sativa on chemotherapy-induced n..." RTHC-00318. Retrieved from https://rethinkthc.com/research/machado-2008-therapeutic-use-of-cannabis
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.