Biochem/Physiol Actions | Cisapride is a parasympathomimetic which acts as a serotonin 5-HT4 agonist. Stimulation of the serotonin receptors increases acetylcholine release in the enteric nervous system. Cisapride stimulates motility of the upper gastrointestinal tract without stimulating gastric, biliary, or pancreatic secretions. Cisapride increases the tone and amplitude of gastric (especially antral) contractions, relaxes the pyloric sphincter and the duodenal bulb, and increases peristalsis of the duodenum and jejunum resulting in accelerated gastric emptying and intestinal transit. It increases the resting tone of the lower esophageal sphincter. It has little, if any, effect on the motility of the colon or gallbladder. Cisapride does not induce muscarinic or nicotinic receptor stimulation, nor does it inhibit acetylcholinesterase activity. Cisapride is a substituted piperidinyl benzamide prokinetic agent. Cisapride facilitates release of acetylcholine from the myenteric plexus, resulting in increased gastrointestinal motility. In addition, cisapride has been found to act as a serotonin agonist, stimulating type 4 receptors, and a serotonin 5-HT3 receptor antagonist. |
