IN EXPERIMENTAL AND CLINICAL STUDIES ITOPRIDE HAS BEEN OBSERVED TO PRODUCE PROKINETIC AND ANTIEMETIC EFFECTS. IT STIMULATES MOTILITY OF THE UPPER PART OF THE GASTROINTESTINAL TRACT WITHOUT AFFECTING GASTRIC, BILIARY, OR PANCREATIC SECRETION. SPECIFICALLY, IT INCREASES GASTRIC AND DUODENAL PERISTALSIS, AND LOWER OESOPHAGEAL SPHINCTER TONE. ALSO, IT RELAXES PYTORIC SPHINCTER, ACCELERATES GASTRIC EMPTYING, AND DECREASES INTESTINAL TRANSIT TIME. IT INHIBITS APOMORPHINE-INDUCED VOMITING IN A DOSE-DEPENDENT MANNER. IT PROMOTES MOTILITY OF THE UPPER PART OF THE GASTROINTESTINAL TRACT BY DUAL MECHANISMS. FIRST, IT ACTS AS AN ANTAGONIST OF DOPAMINE D2 RECEPTOR AND THEREBY INCREASES THE RELEASE OF ACETYLCHOLINE (ACH) BY CHOLINERGIC ENTERIC NEURONS. SECOND, IT INHIBITS THE INACTIVATION OF ACH BY THE ENZYME ACETYLCHOLINESTERASE. BOTH THESE ACTIONS LEAD TO INCREASED ACH LEVELS IN THE GASTROINTESTINAL TRACT. INCREASED AVAILABILITY OF ACH ENHANCES GASTROINTESTINAL MOTILITY AND GASTRIC EMPTYING BECOMES QUICKER. ITS CENTRAL ANTIDOPAMINERGIC ACTION AT THE MEDULLARY CHEMORECEPTOR TRIGGER ZONE ACCOUNTS FOR ITS ANTIEMETIC EFFECT.