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

Gastroenterology. 1999 Feb;116(2):239-47. doi: 10.1016/s0016-5085(99)70118-6.


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 <4 (P < 0.02) and 49.2% in subjects with an on-treatment gastrin of >25 ng. L-1 vs. 19.8% in those with a fasting gastrin of <25 ng. L-1 (P < 0.006). At day 15 after omeprazole treatment, the H. pylori-positive subjects showed a heterogeneous response with some having increased acid output and others persisting suppression.

Conclusions: Rebound acid hypersecretion occurs in H. pylori-negative subjects after omeprazole treatment. Its severity is related to the degree of elevation of pH on treatment. Persisting suppression of acid secretion masks the phenomenon in H. pylori-positive subjects.

MeSH terms

  • Adult
  • Anti-Ulcer Agents / pharmacology*
  • Case-Control Studies
  • Enzyme Inhibitors / pharmacology*
  • Female
  • Gastric Acid / metabolism*
  • Gastric Mucosa / drug effects*
  • Gastric Mucosa / metabolism*
  • Gastric Mucosa / microbiology
  • Helicobacter Infections / drug therapy*
  • Helicobacter Infections / microbiology
  • Helicobacter pylori*
  • Humans
  • Male
  • Omeprazole / pharmacology*
  • Severity of Illness Index


  • Anti-Ulcer Agents
  • Enzyme Inhibitors
  • Omeprazole