<prompt> Antiemetic effect of metoclopramide is mainly due to its action as:5HT3 antagonistD2 antagonistM3 antagonist5HT4 agonist  <response>: Ans. B D2 antagonistRef: Katzung 13th1070, KDT 8the p713Metoclopramide 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 