THE EFFECT OF DIFFERENT DOSAGE SCHEDULES OF CISAPRIDE ON GASTRIC-EMPTYING IN IDIOPATHIC GASTROPARESIS

The aim of this study was to determine the optimal dosage regimen of c isapride for the treatment of idiopathic gastroparesis. We studied 17 patients with documented idiopathic gastroparesis in a three-way, cros s-over, double-blind study with three 4-day treatment periods separate d by at least 3 days without treatment. In each period. the patients w ere preloaded with cisapride (10 mg tid) for three days. On cake fourt h day (the test day) they took either 10 mg or 20 mg before breakfast and placebo before lunch (I x 10 mg), (I x 20 mg), or to mg before bre akfast and 10 mg before lunch (2 x 10 mg). The medications were taken 30 min before meals. Gastric emptying of solids (Tc-99m-sulphur colloi d) was measured at lunch time under basal conditions and during each t reatment period. Plasma concentrations of cisapride were determined be fore the breakfast dose, before cake lunch dose, and at 1, 2, 3, 4 and 5 h after. The greatest acceleration in gastric emptying occurred wit h the 2 x 10 mg regimen. Although cake single morning dose of 20 mg al so significantly accelerated gastric emptying (P = 0.05), the reductio n was not as substantial. Plasma concentrations of cisapride were sign ificantly higher after 2 x 10 mg than after 1 x 20 mg or 1 x 10 mg. Th ere was a significant relation between cisapride plasma concentrations and changes in gastric emptying. Peak concentrations of cisapride gre ater than 60 ng . ml-1 were invariably associated with acceleration of gastric emptying. We conclude that cisapride 10 mg tid before meals i s the optimal dose for the treatment of idiopathic gastroparesis.