Cisapride
Mechanism :
Cisapride promotes gastric motility. The mechanism of action of cisapride is thought to be primarily enhancement of release of acetylcholine at the myenteric plexus. Cisapride does not induce muscarinic or nicotinic receptor stimulation, nor does it inhibit acetylcholinesterase activity.
Indication :
Contraindications :
Serious cardiac arrhythmias including ventricular tachycardia, ventricular fibrillation, torsades de pointes, and QT prolongation have been reported in patients taking cisapride with other drugs that inhibit cytochrome P450 3A4. Some of these events have been fatal.
Dosing :
0.5-1.3 mg/kg/dose PO 6-8 hourly;
Maximum: 10 mg/dose.
Adverse Effect :
Headache, dizziness, vomiting, depression, diarrhea, abdominal pain, dry mouth, somnolence, palpitation, migraine, tremor, tachycardia, elevated liver enzymes, thrombocytopenia, leukopenia, aplastic anemia, pancytopenia, granulocytopenia, cardiac arrhythmias (ventricular tachycardia, ventricular fibrillation, torsades de pointes and QT prolongation).
Interaction :
Clarithromycin, Erythromycin: Markedly inhibit the metabolism of cisapride, which can result in an increase in plasma cisapride levels and prolongation of the QT interval on the ECG.
Anticholinergics: Expected to compromise the beneficial effects of cisapride.
Anticoagulants (Oral): The coagulation times were increased in some cases.
Antidepressants: Nefazodone inhibits the metabolism of cisapride, which can result in an increase in plasma cisapride levels and prolongation of the QT interval on the ECG
Fluconazole, Itraconazole, and Oral Ketoconazole: inhibits the metabolism of cisapride, which can result in an increase in plasma cisapride levels and prolongation of the QT interval on the ECG.
H2 Receptor Antagonists: The gastrointestinal absorption of cimetidine and ranitidine is accelerated when they are coadministered with cisapride.
Protease Inhibitors: Indinavir and ritonavir markedly inhibit the metabolism of cisapride which can result in an increase in plasma cisapride levels and prolongation of the QT interval on the ECG.
Hepatic Dose :
Reduce the dose by half in patients with hepatic impairment.