Effect of H2-receptor antagonists on gastric acid secretion and serum gastrin concentration: a review.

Cimetidine inhibits basal and nocturnal acid secretion and acid secretion stimulated by histamine, pentagastrin, caffeine, insulin, sham feeding, and food. Cinetidine (300 mg) inhibits basal acid secretion in duodenal ulcer patients by 95% for at least 5 hr. When taken at bedtime, cimetidine inhibits nocturnal acid secretion by greater than 80% for most of the night. Cimetidine markedly inhibits food-stimulated acid secretion and is more effective than anticholinergic drugs. However, to get adequate suppression of food-stimulated acid secretion throughout the day, cimetidine should be given with each meal. Cimetidine has no effect on nocturnal serum gastrin concentration, but, when stimulated by food, serum gastrin concentration is higher after cimetidine than after placebo.