[6] In many countries, it has been either withdrawn or had its indications limited because of reports of the side-effect long QT syndrome, which may cause arrhythmias.

The U.S. Food and Drug Administration (FDA) issued a warning letter to doctors,[7] and cisapride was voluntarily removed from the U.S. market on July 14, 2000.

[8] Cisapride is still available in the United States and Canada for use in animals, and is commonly prescribed by veterinarians to treat megacolon in cats.

[9] As a prokinetic agent that increases gastrointestinal motility, cisapride acts as a selective serotonin agonist in the 5-HT4 receptor subtype.

Cisapride also relieves constipation-like symptoms by indirectly stimulating the release of acetylcholine, which acts on muscarinic receptors.