One-week versus two-week H2-receptor antagonist in combination with amoxicillin and tinidazole for eradication of Helicobacter pylori infection.

BACKGROUND/AIMS: Eradication regimens combining two antibiotics with a proton pump inhibitor have been studied intensively in Helicobacter pylori (H. pylori) infection; however, only a few reports have focused on the role of H2-receptor antagonists (H2-RAs) in eradication therapy. The mechanism involved in the synergy between antibiotics and H2RAs are still elusive. So we compared the efficacy of two regimens: a 1-week or 2-week course of high-dose H2-RA-based triple therapy in patients with H. pylori infection, and assessed the impact of primary resistance for metronidazole on the treatment outcome.

METHODOLOGY

One hundred and twenty patients with peptic ulcers and nonulcer dyspepsia were randomly assigned to a one-week course of famotidine 40mg b.i.d., amoxicillin lg b.i.d. and tinidazole 500 mg b.i.d. (FAT1 group; n = 60) or a 2-week course of famotidine 40 mg b.i.d., amoxicillin lg b.i.d. and tinidazole 500 mg b.i.d. (FAT2 group; n = 60). Upper endoscopy was performed prior to treatment and at least 4 weeks after completion of treatment and discontinuation of the antisecretory therapy. H. pylori status was assessed by biopsy urease test, histology and culture.

RESULTS

In the intention-to-treat analysis, eradication of H. pylori was achieved in 38 of 60 patients (63.3%; 95% CI: 51-76%) in the FAT1 group, compared to 48 of 60 patients (80%; 95% CI: 70-92%) in the FAT2 group (NS). In the per protocol analysis, eradication therapy was achieved in 38 of 54 patients (70.4%; 95% CI: 58-82%) in the FAT1 group and 48 of 53 patients (90.6%; 95% CI: 83-98%) in the FAT2 group (p < 0.05). The overall eradication rates for strains susceptible and resistant to metronidazole were 79.7% (95% CI: 71-89%) vs. 60% (95% CI: 44-74%) in the intention-to-treat analysis (p = 0.016) and 84% (95% CI: 76-92%) vs. 71.9% (95% CI: 56-88%) in the per protocol analysis (p = 0.12). Seven patients in the FAT1 group and six patients in the FAT2 group available for follow-up reported adverse events (11.7% and 10% respectively) without necessity of discontinuation of the study medications. Serious adverse events were not observed.

CONCLUSIONS

A 2-week course of high-dose H2-RA-based triple therapy is well tolerated and sufficiently effective in eradicating H. pylori infection. Presence of metronidazole resistance has a negative impact on the treatment efficacy.