Effect of mifentidine, a new H2-antagonist, on pentagastrin-stimulated acid secretion in healthy subjects.

The purpose of this study is to investigate the effects of a single oral dose of 10 mg of mifentidine, a new H2-receptor antagonist, on unstimulated and pentagastrin-stimulated gastric acid secretion in healthy subjects. The study was carried out in a double-blind randomized, placebo controlled, cross-over design. Ten subjects were given both placebo and active drug, with a wash-out period of at least 3 days. Unstimulated acid secretion was measured in the period between 1 and 1.5 h after drug administration. Immediately thereafter, 2 micrograms/kg/h of pentagastrin was infused intravenously and pentagastrin-stimulated gastric acid secretion was determined for two subsequent hours. The volume of gastric secretion was significantly less after mifentidine than after placebo during the pentagastrin-stimulated period. Acid output was inhibited during unstimulated and pentagastrin-stimulated secretion by mifentidine by 45% and 39% of the placebo values, respectively. No adverse clinical or laboratory effects were noted during the study. The results of this study indicate that mifentidine, given as a single oral dose of 10 mg, inhibits effectively unstimulated and pentagastrin-stimulated acid secretion in healthy subjects.