gastrins and mifentidine

Mifentidine is a new H2-receptor antagonist with distinct characteristics of potency and long plasma half-life. The aim of this study was to evaluate the effects of mifentidine on peptone meal-stimulated gastric acid secretion. Nine duodenal ulcer patients in remission were enrolled in the study and given in double-blind and at random, on two different occasions, a single tablet of 10 or 20 mg mifentidine or placebo according to an incomplete balanced block design. Ninety min after ingestion of the drug, basal gastric secretion was collected for 30 min and volume, pH and acid output determined. Thereafter, the acid output following peptone meal-stimulation was measured for 2 h by a modified version of the intragastric titration method of Thompson and Swierczek. Plasma samples were collected for gastrin and mifentidine determinations. Basal acid output was strongly inhibited by both the low dose (-78%) and the high dose (-98%) (p less than 0.01). The peptone meal-stimulated acid output was reduced in a dose-dependent manner (-45% by 10 mg and -90% by 20 mg). The drug did not affect the fasting serum gastrin levels but increased, although not significantly, the gastrin response to food. The log of the area under the mifentidine plasma levels correlated linearly with total acid output (p less than 0.01). The results of this study indicate that mifentidine dose-dependently suppresses basal acid secretion and reduces peptone-stimulated gastric acid secretion in duodenal ulcer patients.

Topics: Adult; Clinical Trials as Topic; Double-Blind Method; Duodenal Ulcer; Female; Food; Gastric Acid; Gastrins; Humans; Imidazoles; Male; Middle Aged; Peptones; Random Allocation

A study has been done in 10 duodenal ulcer patients of the effect of a single oral dose of 10 mg mifentidine on the acid and pepsin responses to sham feeding after 1 h 30 min and to pentagastrin after 4 h 15 min. The study followed a double-blind, randomized, placebo-controlled, cross-over design. Gastric juice was collected for 5 h 15 min after treatment. Blood was sampled for up to 3 h 30 min to determine the effects of mifentidine on serum gastrin. Mifentidine suppressed basal acid output by 77% and sham feeding-stimulated acid output by 71% vs the placebo values. Pentagastrin-stimulated acid output was inhibited by 30% throughout the pentagastrin infusion. The suppressant effect of the drug on pepsin output was not as marked as on acid secretion. Mifentidine did not affect the serum gastrin level during the basal and sham feeding phases. No untoward effects were reported by the patients. The results show that 10 mg mifentidine p.o. produced a large reduction in the acid output in response to sham feeding and pentagastrin without affecting the serum gastrin responses.

Topics: Adult; Duodenal Ulcer; Eating; Female; Gastric Acid; Gastrins; Histamine H2 Antagonists; Humans; Imidazoles; Male; Middle Aged; Pentagastrin; Pepsin A