Effect of short-term treatment with regular or high doses of omeprazole on the detection of Helicobacter pylori in bleeding peptic ulcer patients

Background: It is unknown whether short-term regular or high-dose omeprazole has any influence on the colonization of Helicobacter pylori in the stomach. We therefore studied the effect of 3-day treatment of 2 different doses of omeprazole. Methods: H. pylori-positive patients with peptic ulcer bleeding (n=101) were randomized to receive either a regular dose (20 mg/day for 3 days)(n=51) or a high dose of omeprazole (80 mg bolus + 8 mg/h infusion/day for 3 days) (n=50). H. pylori status was assessed by histology and urease testing of gastric biopsies pre-entry and after 3-day therapy. Results: With the high dose of omeprazole, tests for the diagnosis of H. pylori became negative significantly more often than with the regular dose (60% versus 27.5%, P=0.001 (any test), 67.6% versus 31.7%, P=0.003 (histology) and 82.2% versus 43.6%, P=0.001 (urease test)). Conclusion: Conversion of the H. pylori tests negative after 3-day treatment of omeprazole is dose-dependent. The diagnosis of H. pylori infection depends on the timing of biopsies in relation to the beginning of proton-pump inhibitor treatment. If samples to find H. pylori are not taken before the treatment, the presence of the bacteria may be overlooked.