Cisapride vs metoclopramide

Radionuclide gastric solid-phase emptying was studied in 10 subjects with diabetic gastroparesis comparing the acute intravenous administration of cisapride (2.5, 5, 10 mg), placebo, and metoclopramide (10 mg). No hemodynamic or electrocardiographic changes were noted. While both cisapride and metoclopramide normalized impaired solid emptying, cisapride at its highest dosage (10 mg) resulted in significantly faster gastric emptying (P=0.003) than metoclopramide. The effects of cisapride were dose related and correlated well (r=0.48,P<0.01) with the plasma drug levels. Clinical studies of chronic oral usage must take into account the dose-related response and factors affecting blood levels.