Effect of omeprazole on duodenal ulcer-associated antral gastritis and Helicobacter pylori

This study set out to investigate the effects of omeprazole or ranitidine on the progression of antral gastritis and Helicobacter pylori in patients with active duodenal ulcer. A double-blind, double-dummy trial was performed in 270 patients, 241 of whom were studied histologically for the presence of H. pylori. Patients were randomized to receive omeprazole, 10 mg every morning, omeprazole, 20 mg every morning, or ranitidine, 150 mg twice a day, for four weeks. Endoscopy was performed on entry and at weekly intervals during the study; at least two antral biopsies were taken on each occasion to assess the activity and degree of chronic inflammation, as reflected by the degree of polymorphonuclear leukocyte infiltration and mononuclear cell infiltration, respectively. Biopsy specimes also were assessed histologically for H. pylori. The sex, age and maximal acid output were comparable in the three treatment groups. The percentages of patients showing an improvement in the activity of gastritis in the four consecutive weeks of treatment were 9%, 40%, 51%, and 53% for omeprazole, 10 mg (N=78); 14%, 42%, 49%, and 53% for omprazole, 20 mg (N=81); and 2%, 23%, 30%, and 33% for ranitidine, 150 mg twice a day (N=82) (life table analysis gave P<0.01 for both omeprazole regimens compared with ranitidine). The degree of chronic inflammation showed similar changes. The density of H. pylori decreased significantly after treatment with omeprazole, 10 mg or 20 mg, (both, P<0.00001) but not with ranitidine. The reduction in bacterial density was significantly higher (P<0.003) in those who showed improvement of gastritis than in those who did not. We conclude that effective acid inhibition with omeprazole improves antral gastritis and is accompanied by a reduction in antral bacterial density, suggesting that both acid and H. pylori may be involved in the pathogenesis of antral gastritis.