Hp and pH--the relevance of gastric acid to the treatment of Helicobacter pylori infection.

Helicobacter pylori infection causes inflammation of the gastric and duodenal mucosa, which results in a disturbance of the regulation of gastrin, gastric acid, and pepsin secretion. Acid secretion may be diminished, normal, or increased, depending on the stage of H. pylori infection, although the meal-stimulated gastrin response is invariably elevated. The exact mechanisms involved are not known, but probably involve the release of cytokines in response to bacterial products initiating mucosal inflammation. Helicobacter pylori is suppressed, although not eradicated, by proton pump inhibitors. In various dose combinations with amoxycillin, omeprazole in a twice daily dose of up to 40 mg b.i.d. eradicates the organism in up to 82% of patients. This synergistic effect may be due to the direct effects of omeprazole, the protection of amoxycillin from acid degradation, or the enhancement of host defense mechanisms accompanying acid suppression.