<prompt> Metaclopramide all are true except ?Increase gastric emptyingD2-agonistActs on CTZLong term use can cause parkinsonism, galactorrhoea and gynaecomastia  <response>: Ans. is b i.e., D,-agonist Metaclopramide is D2-antagonist not agonist. Metoclopramide Metoclopramide is aprokinetic drug. It has more prominent effect on upper GIT- increases gastric peristalsis, while relaxing the pylorus and the first pa of duodenum - speed gastric emptying. Tone of lower esophageal sphincter LES is increased and gastroesophageal reflux opposed. But has no significant action on colonic motility. An effective antiemetic. Mechanism of action. I. 5-HT4agonism - stimulation of 5-HT4 receptor in GIT enhances the release of ACH from myenteric plexus - Main prokinetic action of metoclopropamide is due to this action. D2 antagonism - Blockade of D2 receptor in CTZ is mainly responsible for antiemetic effect. D2 receptor blockade in GIT is responsible for some prokinetic action also. Adverse effects - Sedation, dizziness, loose stools, muscle dystonia especially in children are the main side effects. D2 -blocking action may cause extrapyramidal symptoms Akathsia, Parkinsonism and hyperprolactinemia galactorrhea, gynacomastia. 