A morpholine-based antiemetic, which is or the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy. Aprepitant is a selective high-affinity antagonist of human substance P/neurokinin 1 (NK1) receptors. ChEBI: Aprepitant is a morpholine-based antiemetic, which is or the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy. Aprepitant is a selective high-affinity antagonist of human substance P/neurokinin 1 (NK1) receptors. It has a role as an antidepressant, an antiemetic, a peripheral nervous system drug, a neurokinin-1 receptor antagonist and a substance P receptor antagonist. It is a member of triazoles, a member of morpholines, a cyclic acetal and a member of (trifluoromethyl)benzenes.