Use of Cannabinoids in Cancer Patients

CINV is regulated via different pathways, one of which appears to be the endocannabinoid system. CB1 receptor agonists decrease GI motility, but may also act centrally. Cannabinoids have been shown to be efficacious at reducing CINV when compared to placebo or other antiemetics. However, there is limited evidence comparing medical cannabis to newer generation antiemetics such as serotonin antagonists and substance P/neurokinin-1 receptor antagonists. ASCO guidelines recommend using FDA approved cannabinoids for nausea and vomiting that does not respond to other agents, but cite lack of evidence for using other formulations. As reported by the National Academies of Sciences Engineering and Medicine, there is “conclusive evidence that oral cannabinoids are effective” in treating CINV. Even with systematic reviews showing benefit, the Cochrane Database review recommends only using cannabinoids when patients have failed other antiemetics. There are a lack of data for using plant cannabis, despite patient perceptions and requests. Prospective, randomized trials utilizing preparations that limit THC to avoid undesired side effects are needed. There is a randomized controlled trial underway in Australia (“Cannabis CINV”) which will compare an oral THC/CBD formulation with placebo. (II)