Rebound hypersecretion after omeprazole and its relation to on-treatment acid suppression and Helicobacter pylori status

Background & Aims: There have been conflicting reports regarding acid secretion after treatment with omeprazole. This study examined acid secretion after treatment with omeprazole and its relation to Helicobacter pylori status and on-treatment gastric function. Methods: Twelve H. pylori–negative and 9 H. pylori–positive subjects were examined before, on, and at day 15 after an 8-week course of 40 mg/day omeprazole. On each occasion, plasma gastrin, intragastric pH, and acid output were measured basally and in response to increasing doses of gastrin 17. Results: In the H. pylori–negative subjects at day 15 after omeprazole treatment, basal acid output was 82% higher ( P < 0.007) and maximal acid output 28% higher ( P < 0.003) than before omeprazole. The degree of increase in maximal acid output was related to both on-treatment pH and on-treatment fasting gastrin levels, being 48.0% in subjects with an on-treatment pH of >4 vs. 21.0% in those with a pH of 25 ng · L −1 vs. 19.8% in those with a fasting gastrin of