Antiemetic effect of metoclopramide is mainly due to its action as:
Ans. (B) D2 antagonist(Ref: Katzung 13th/1070, KDT 8th/e p713)Metoclopramide has action on several receptors.Main action as anti-emetic is because of D2 receptor antagonism.Main action as prokinetic is because of 5HT4 agonism.Mechanism of actions of metoclopramideReceptorActionClinical effectD2AntagonismAnti-emetic5HT3AntagonismAnti-emeticProkinetic5HT4AgonismProkinetic
5HT3 antagonist
D2 antagonist
M3 antagonist
5HT4 agonist
Anti-Emetic