Helicobacter pylori augments the pH-increasing effect of omeprazole in patients with duodenal ulcer

Gastroenterology. 1996 Mar;110(3):725-32. doi: 10.1053/gast.1996.v110.pm8608881.


Background & aims: Omeprazole is less effective in healthy subjects than in patients with duodenal ulcers. The aim of this study was to determine whether Helicobacter pylori augments the pH-increasing effect of omeprazole in patients with duodenal ulcers.

Methods: In 16 patients with duodenal ulcers, baseline intragastric acidity was measured before and 4-6 weeks after the cure of H. pylori infection. In 17 patients with duodenal ulcers, 24-hour pH metry was performed during treatment with 20 mg omeprazole once daily before as well as after eradication of H. pylori. Intragastric acidity was measured using a glass electrode placed 5 cm below the cardia. H. pylori infection was assessed by [13C] urea breath test, culture, histology, and rapid urease test.

Results: H. pylori eradication resulted in marked decrease of the pH-increasing effect of omeprazole (24-hour median gastric pH, 5.5 vs. 3.0; P<0.002) that was most pronounced during nighttime (median gastric pH, 6.4 vs. 2.1; P=0.001). On the other hand, baseline intragastric pH remained unchanged after eradication (median gastric pH, 1.0 vs. 1.1; P=0.5).

Conclusions: In patients with duodenal ulcers treated with omeprazole, intragastric pH depends significantly on the presence or absence of H. pylori, whereas baseline pH remained unchanged after H. pylori eradication.

Publication types

  • Clinical Trial
  • Controlled Clinical Trial

MeSH terms

  • Adult
  • Aged
  • Anti-Ulcer Agents / therapeutic use*
  • Duodenal Ulcer / drug therapy*
  • Duodenal Ulcer / etiology
  • Duodenal Ulcer / metabolism
  • Female
  • Gastric Acid / metabolism*
  • Gastric Acidity Determination
  • Gastritis / etiology
  • Helicobacter Infections / complications
  • Helicobacter Infections / drug therapy
  • Helicobacter pylori / physiology*
  • Humans
  • Hydrogen-Ion Concentration
  • Male
  • Middle Aged
  • Omeprazole / therapeutic use*


  • Anti-Ulcer Agents
  • Omeprazole