Compartive inhibition of coffee-induced gastric acid secretion employing misoprostol and cimetidine

Abstract

Six healthy subjects (three men, three women) were studied to compare the effects of misoprostol and cimetidine on coffee-induced gastric secretion. Gastric secretion was measured after a 12-hr fast according to the Hobsley method, employing phenolsulfonphthalein (PSP) as a marker. Each subject was studied on three occasions separated by at least one week: (1) as control, basal gastric secretion was measured followed by sample collection after oral placebo and then coffee; (2) basal gastric secretion was measured followed by sample collection after 200 μg of misoprostol and then coffee; (3) basal gastric secretion was measured followed by 200 mg of cimetidine and then coffee. The order of treatment was randomized. Basal gastric secretion collection, sample collection, and the administration of coffee were carefully standardized. Titratable acidity; acid output; and sodium, potassium, chloride, and PSP concentrations were measured in each sample to assess hydrogen ion secretion, pyloric losses, and duodenogastric reflux. Mathematical corrections were available for the last. Results confirmed that coffee is associated with a marked rise in titratable acidity, peak acid output (PAO), and volume with a modest fall in mean gastric pH. Both misoprostol and cimetidine lowered titratable acidity, compared with placebo (P=0.03). Mean PAO was reduced by both misoprostol and cimetidine in a similar manner, and there was a significant difference between the three treatment groups (P=0.02). These findings document and confirm the antisecretory effect of a single oral dose (200 μg) of misoprostol on gastric secretion.