Background: The efficacy of proton pump inhibitor based triple therapy in patients from South-East Asia, where metronidazole resistance is reportedly high, has not been formally assessed in randomized, multicentre trials.
Aim: To compare the eradication rates of Helicobacter pylori, ulcer healing rates and side-effects of three regimens of omeprazole triple therapy in patients with duodenal ulcer from South-East Asia and to study the impact of metronidazole resistance.
Methods: A single blind, randomized parallel group, comparative multicentre study. A total of 246 patients from 15 centres in four South-East Asian countries were randomized to receive OAC (omeprazole 20 mg b.d., amoxycillin 1 g b. d., clarithromycin 500 mg b.d.), OAM (omeprazole 20 mg b.d., amoxycillin 1 g b.d., metronidazole 400 mg b.d.) or OMC (omeprazole 20 mg b.d., metronidazole 400 mg b.d., clarithromycin 500 mg b.d.) for 7 days. After triple therapy, the patients were further randomized to receive either omeprazole or placebo for 7 days. Upper gastrointestinal endoscopy was performed before treatment and 4 weeks after treatment. Biopsies for culture and for histopathological examination for H. pylori were taken from corpus and antrum before treatment and 4 weeks after treatment.
Results: The eradication rates were intention-to-treat/per protocol (95% CI): OAC 87% (79-94%)/94% (89-100%); OAM 80% (70-89%)/91% (83-98%); OMC 85% (77-93%)/94% (88-100%). The difference in eradication rates between the three groups was not statistically significant (P=0.419). Pre-treatment metronidazole resistance, was found in 34% of isolates and was a significant prognostic factor in patients receiving OAM (odds ratio 5.26) but not in patients receiving OAC or OMC.
Conclusions: All three treatment regimens were safe, well tolerated and highly effective for eradication of H. pylori and ulcer healing. Pre-treatment metronidazole resistance reduced the efficacy of OAM but did not affect the efficacy of OMC.