One-week triple therapy with omeprazole, amoxycillin and tinidazole for Helicobacter pylori infection: The significance of imidazole resistance

Background: Triple therapy involving a proton pump inhibitor and two antibiotics has been suggested as an effective treatment for Helicobacter pylori infection. The impact of imidazole resistance on the efficacy of such regimens is largely unknown. Methods: One hundred patients with culture proven H. pylori infection were treated with omeprazole 40 mg b.d., amoxycillin 1000 mg b.d., and tinidazole 500 mg b.d. for one week. Pre-treatment imidazole susceptibility was measured by disk diffusion. Resistance was confirmed by E-test. Eradication was assessed by endoscopy 6-8 weeks after the end of treatment. In cases of doubt a C-13-urea breath test was performed. Side-effects were scored using a semiquantitative scale. Results: H. pylori was eradicated in 95% of the patients with an imidazole-susceptible strain and in 69% of the patients with a resistant strain (P < 0.005). Significant side-effects were seen in 12%. Conclusion: This proton pump inhibitor triple therapy is a simple, reasonably effective regimen with few significant side-effects. The efficacy is dependent on the susceptibility of the infecting H. pylori strain.