Trimethobenzamide is a blocker of the D₂ receptor. Trimethobenzamide is an antiemetic used to prevent nausea and vomiting. IC50 & Target: D₂ receptor^[1] In Vitro: Trimethobenzamide is a (non-phenothiazine) benzamide antiemetic that acts centrally to block D2 receptors, thereby inhibiting the medullary chemoreceptor trigger zone by blocking emetic impulses to the vomiting center^[1]. In Vivo: The oral bioavailability of Trimethobenzamide is 60% to 100%. The time to peak is about 45 minutes after oral administration and; Intramuscular (I.M.) administration about 30 minutes after intramuscular administration^[1].