Oral THC/CBD capsules improved chemo nausea when standard anti-nausea drugs failed
In a phase II crossover trial of 72 cancer patients with refractory chemotherapy-induced nausea and vomiting, oral THC:CBD capsules nearly doubled the complete response rate compared to placebo (25% vs 14%), and 83% preferred cannabis to placebo.
Quick Facts
What This Study Found
Complete response improved from 14% with placebo to 25% with THC:CBD (RR 1.77, p=0.041). Similar improvements were seen for absence of emesis, use of rescue medications, and quality-of-life scores. However, 31% experienced moderate or severe cannabinoid-related side effects like sedation and dizziness.
Key Numbers
81 randomized, 72 completed efficacy analysis. Complete response: 25% THC:CBD vs 14% placebo (RR 1.77, 90% CI 1.12-2.79). 31% had moderate-severe cannabinoid side effects. 83% preferred cannabis. Median age 55, 78% female.
How They Did This
Phase II, multicentre, double-blind, placebo-controlled crossover trial. Patients who experienced CINV despite guideline-consistent antiemetics received self-titrated THC 2.5mg/CBD 2.5mg capsules (1-4 capsules, three times daily, days -1 to 5) or matching placebo across two chemotherapy cycles.
Why This Research Matters
This is one of the first rigorous trials of standardized oral THC:CBD for refractory chemotherapy nausea, a significant unmet need since many patients fail standard antiemetics.
The Bigger Picture
The strong patient preference (83%) for cannabis despite notable side effects suggests patients found the nausea relief worth the trade-off, supporting further investigation in the planned phase III expansion.
What This Study Doesn't Tell Us
Small phase II sample. Self-titrated dosing introduces variability. The 31% rate of moderate-severe side effects (sedation, dizziness, disorientation) is significant and may limit practical use.
Questions This Raises
- ?Will the phase III trial with 170 additional participants confirm these findings?
- ?Can dosing optimization reduce side effects while maintaining efficacy?
- ?How does THC:CBD compare to other rescue antiemetics?
Trust & Context
- Key Stat:
- 83% of patients preferred THC:CBD to placebo
- Evidence Grade:
- Strong: randomized, double-blind, placebo-controlled crossover design, though limited by phase II sample size.
- Study Age:
- Published in 2020 in Annals of Oncology.
- Original Title:
- Oral THC:CBD cannabis extract for refractory chemotherapy-induced nausea and vomiting: a randomised, placebo-controlled, phase II crossover trial.
- Published In:
- Annals of oncology : official journal of the European Society for Medical Oncology, 31(11), 1553-1560 (2020)
- Authors:
- Grimison, P, Mersiades, A, Kirby, A, Lintzeris, N, Morton, R, Haber, P, Olver, I, Walsh, A, McGregor, I, Cheung, Y, Tognela, A, Hahn, C, Briscoe, K, Aghmesheh, M, Fox, P, Abdi, E, Clarke, S, Della-Fiorentina, S, Shannon, J, Gedye, C, Begbie, S, Simes, J, Stockler, M
- Database ID:
- RTHC-02590
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
How much did nausea improve?
Complete response (no vomiting, no rescue medication) nearly doubled from 14% with placebo to 25% with THC:CBD. Quality-of-life scores related to nausea also improved.
What were the side effects?
About 31% experienced moderate or severe cannabinoid-related side effects including sedation, dizziness, and disorientation. No serious adverse events were attributed to THC:CBD, and 83% still preferred it over placebo.
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Cite This Study
https://rethinkthc.com/research/RTHC-02590APA
Grimison, P; Mersiades, A; Kirby, A; Lintzeris, N; Morton, R; Haber, P; Olver, I; Walsh, A; McGregor, I; Cheung, Y; Tognela, A; Hahn, C; Briscoe, K; Aghmesheh, M; Fox, P; Abdi, E; Clarke, S; Della-Fiorentina, S; Shannon, J; Gedye, C; Begbie, S; Simes, J; Stockler, M. (2020). Oral THC:CBD cannabis extract for refractory chemotherapy-induced nausea and vomiting: a randomised, placebo-controlled, phase II crossover trial.. Annals of oncology : official journal of the European Society for Medical Oncology, 31(11), 1553-1560. https://doi.org/10.1016/j.annonc.2020.07.020
MLA
Grimison, P, et al. "Oral THC:CBD cannabis extract for refractory chemotherapy-induced nausea and vomiting: a randomised, placebo-controlled, phase II crossover trial.." Annals of oncology : official journal of the European Society for Medical Oncology, 2020. https://doi.org/10.1016/j.annonc.2020.07.020
RethinkTHC
RethinkTHC Research Database. "Oral THC:CBD cannabis extract for refractory chemotherapy-in..." RTHC-02590. Retrieved from https://rethinkthc.com/research/grimison-2020-oral-thccbd-cannabis-extract
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.