Eradication of Helicobacter pylori increases nocturnal intragastric acidity during dosing with rabeprazole, omeprazole, lansoprazole and placebo

Background: The eradication of Helicobacter pylori decreases the antisecretory activity of omeprazole and lansoprazole. Rabeprazole is a potent proton pump inhibitor that may not be affected as greatly by H. pylori status. Aim: To compare the effect of H. pylori eradication on intragastric acidity and plasma gastrin during dosing with lansoprazole, omeprazole, rabeprazole and placebo. Methods: Twenty-four healthy H. pylori -infected volunteers were studied on day 7 of dosing with placebo, lansoprazole 30 mg, omeprazole 20 mg and rabeprazole 20 mg, before and at least 5 weeks after H. pylori eradication. On each occasion, the 24-h intragastric acidity was measured by gastric aspiration. Plasma gastrin concentrations were measured hourly from 08.00 to 13.00 h. Results: Sixteen subjects completed the study. For all three drugs and placebo, H. pylori eradication increased intragastric acidity, particularly nocturnal acidity, and decreased plasma gastrin. There were no differences between the three drugs with respect to 24-h acidity, percentage of time pH > 4 or 5-h plasma gastrin, either before or after H. pylori eradication. Before eradication, the percentage nocturnal time at pH > 3 was significantly greater during rabeprazole than during lanso-prazole dosing. Conclusions: The increase in intragastric acidity seen after H. pylori eradication during dosing with proton pump inhibitors is a drug-class effect, particularly affecting nocturnal acid control. This is related to increased spontaneous intragastric acidity after H. pylori eradication.