Effects of three H2-receptor antagonists (cimetidine, famotidine, ranitidine) on serum gastrin level.

We investigated the pattern of changes in serum gastrin level produced by three H2-receptor antagonists (H2RA) in patients with gastric and duodenal ulcers between 1990 and 1999. The subjects were 51 patients (cimetidine: 18 patients; famotidine: 16 patients; ranitidine: 17 patients). The gastrin test (in the fasting and meal-stimulated states) was conducted during drug administration and on the fourth day after drug cessation. After cessation of the drug therapy, the fasting serum gastrin level was significantly lower than that during the drug therapy with the three H2RAs. Gastrin level in the fasting test was significantly higher during famotidine therapy than during cimetidine therapy (p = 0.0123). In the meal-stimulated gastrin test, the AUC of gastrin during treatment with H2RA treatment was significantly higher with famotidine than with cimetidine (p = 0.0024). The results indicate different patterns of change in the serum gastrin level in the fasting and meal-stimulated test according to the H2RA administered. Gastrin level was highest in patients administered famotidine and lowest among those administered cimetidine. The pattern of gastrin change in patients administered ranitidine was intermediate between famotidine and cimetidine.