Notes: Cisapride is an agonist of serotonin (5-HT) receptor subtype 5-HT4 (IC50 = 0.483 μM in COS-7 cells expressing the human receptor).{34540} It induces relaxation of precontracted isolated rat esophageal thoracic muscularis mucosae preparations (EC50 = 102.33 nM). Cisapride (0.5 mg/kg) increases the rate of gastric emptying in rats. It is also a human ether-a-go-go related gene (hERG) channel blocker that binds to hERG channels with an IC50 value of less than 1 μM in a fluorescence polarization assay. Formulations containing cisapride have previously been used in the treatment of nocturnal heartburn associated with gastroesophageal reflux disease.