About Metoclopramide It is a dopamine antagonist - antiemetic gastroprokinetic agent. Mechanism of Action of Metoclopramide Metoclopramide acts through both serotonergic and dopaminergic receptors. Metoclopramide binds to Serotonin (5 HT3 &5HT4) and Dopamine (D2) receptor. Antiemetic action: Metoclopramide inhibits Dopamine receptor in the chemoreceptor trigger zone and produces antiemetic action. Intestinal motility modifying action: The binding of Metoclopramide on 5HT4 receptor will activate interneuron and enhance the release of acetylcholine innervating the smooth muscles. This produces gastric emptying and enhances lower esophageal sphincter tone. Migraine: Metoclopramide is used in migraine to relieve nausea and vomiting Anaesthetic adjuncts: It is used preoperatively in order to reduce the post operative vomiting.