Effect of nifedipine on gastric emptying in normal subjects.

We studied the effects of the calcium-channel blocker, nifedipine, on solid and liquid phases of gastric emptying in 10 healthy male volunteers. Each subject underwent a dual-isotope radionuclide gastric emptying determination with and without the preadministration of nifedipine, 30 mg orally, given 20 min prior to ingestion of the test meal over 10 min, following which the subject lay supine under the gamma-counter for 2 hr. Blood samples for measurement of plasma nifedipine concentration were obtained at the time of drug administration and every 30 min throughout the gastric emptying determination. There was a threefold variation in the areas under the plasma nifedipine concentration vs time curve (AUC) obtained in these 10 subjects. Percent gastric retention of either the liquid (water) or the solid (chicken liver) marker was not significantly different after 30 mg oral nifedipine, as compared to the nontreatment day. We concluded that plasma nifedipine concentrations previously reported to be associated with significant esophageal motility effects in humans were not associated with effects on gastric emptying of either liquids or solids.