Decreasing eradicaton rate of Helicobacter pylori infection with metronidazole-based triple therapy. A randomised study.

BACKGROUND: Helicobacter pylori (H. pylori) infection plays an important role in the pathogenesis of duodenal ulcer (DU) disease. Low DU recurrences and reinfection rates were universally described, when treatment was effective. It has been suggested that short-term triple therapy, comprising a proton pump inhibitor plus two antibiotics (clarithromycin, amoxicillin or a nitroimidazole), should be used as first choice in treating H. pylori infection. Nevertheless, conflicting results have been reported on using these treatment regimens in different countries, due to the resistance of H. pylori against one or more antibiotics. Our aim was to compare the efficacy, for H. pylori eradication, of 1-week triple therapy versus 10 and 14-day triple schedules, in patients with a history of recurrent DU. METHODS: A total of 159 patients (85 males, mean age 59.2+/-3.2 years) was randomly treated with a triple therapy including a standard dose of omeprazole twice daily, amoxicillin 1 g twice daily and metronidazole 500 mg twice daily. Fifty-three patients received 1-week triple therapy (Group I), 53 subjects were treated with 10-day triple therapy (Group II) and 53 others with 14-day triple therapy (Group III). H. pylori infection at entry and eradication, at least 4 weeks after therapy had ended, was assessed by 13C urea breath test and histology on biopsies from the antrum and the corpus. RESULTS: Of the 159 subjects randomised into the study, 6 (3 in group II and 3 in group III) were excluded from the per protocol (PP) analysis because of discontinuations. At the end of the course of treatment, the overall H. pylori eradication rate in the intention-to-treat analysis, was 73.5% (39/53) in group I, 71.6% (38/53) in group II and 73.5% (39/53) in group III, without any statistically significant difference. Moreover, the PP analysis also showed no statistical differences, with an eradication rate of 73.5% (39/53) in group I, 76% (38/50) in group II and 78% (39/50) in group III. The reported frequency of side-effects was evenly distributed between the groups, but 6 patients (3.7%) stopped because of adverse events only in groups II and III. CONCLUSIONS: The present study shows that there is no significant difference between the three regimens although the 14-day triple therapy shows a slightly higher H. pylori eradication rate. There is a strong need, in our region, to put forward surveillance programmes to monitor the prevalence of local resistant strains and to guide treatment on the basis of resistance patterns.