CINV

CINV is nausea and/or emesis triggered by cytotoxic chemotherapy, classically divided into acute (≤24 h post-infusion), delayed (>24 h to ~5 days), and anticipatory (conditioned, pre-treatment) subtypes. Pathophysiology involves 5-HT3, NK1, D2, and cannabinoid CB1 receptor signaling in the area postrema and enteric nervous system. Two synthetic cannabinoids carry FDA approval specifically for CINV that has failed conventional antiemetics: dronabinol (Marinol, approved 1985) and nabilone (Cesamet, approved 1985, relaunched 2006). The National Academies of Sciences, Engineering, and Medicine (NASEM 2017) concluded there is conclusive or substantial evidence that oral cannabinoids are effective antiemetics in CINV. The Cochrane review by Smith et al. (2015, Cochrane Database Syst Rev) found that cannabinoids were more effective than placebo and similar to conventional antiemetics in older trials, but with higher rates of dizziness, dysphoria, and sedation; most trials predated modern 5-HT3 antagonists and NK1 antagonists, limiting comparative inference ⚠️. → See also: Dronabinol, Nabilone, THC, CB1 receptor.