Critical effect of Helicobacter pylori infection on the effectiveness of omeprazole for prevention of gastric or duodenal ulcers among chronic NSAID users

Abstract

Background: The recently reported OMNIUM and ASTRONAUT NSAID ulcer prevention trials using omeprazole to prevent endoscopic ulcer recurrence among chronic NSAID users suggested superiority over misoprostol or ranitidine.

Aim: To test the hypothesis the results from the OMNIUM and ASTRONAUT studies would not be generalizible as ulcer healing and ulcer recurrence would differ in relation to Helicobacter pylori status.

Methods: The data regarding H. pylori status were made available by AstraZenca allowing separate analysis of the outcome of those with NSAID ulcers (i.e. without H. pylori infection) and those NSAID use was complicated with the presence of an active H. pylori infection.

Results: Reanalysis confirmed that omeprazole was superior to placebo for the prevention of ulcer recurrence in chronic NSAID users. However, overall omeprazole was not significantly better than the subtherapeutic dose (400 microg/day) of misoprostol (14.5% vs. 19.6%, respectively, p =.93); 400 microg of misoprostol was actually superior to omeprazole for the prevention of gastric ulcers among those NSAID ulcers (8.2% vs. 16.6% for misoprostol and omeprazole, respectively; p <.05). Omeprazole was also not statistically different from misoprostol for gastric ulcer prevention in those whose NSAID use was complicated by an active H. pylori infection. Omeprazole was not significantly different from 300 mg of ranitidine for the prevention of NSAID gastric ulcers (14.6% vs. 11.6%, respectively, p =.56). Duodenal ulcers were over represented among H. pylori infected NSAID users and duodenal ulcer prevention was more sensitive to acid suppression than gastric ulcer.

Conclusion: The OMNIUM and ASTRONAUT trials may have provided an unrealistic sense of security regarding the effectiveness of omeprazole for protection against ulcer recurrence in chronic NSAID users.