Background: In patients with ulcer disease the optimal dose and duration of Helicobacter pylori treatment containing omeprazole (O), metronidazole (M) and clarithromycin (C) has yet to be established. The efficacy might be influenced by metronidazole- and clarithromycin-resistance.
Aim: To study the effect of duration of OMC treatment on its efficacy and influence of metronidazole-resistance and clarithromycin-resistance on the optimal duration.
Materials and methods: Ulcer patients (n=76) were randomized to three double-blind treatments of 10 days: OMC 4 consisted of 4 days b.d. 20 mg omeprazole, 400 mg metronidazole and 250 mg clarithromycin switched over to 6 days b.d. 20 mg omeprazole and placebo antibiotics (n=27); OMC 7 consisted of 7 days b.d. omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg and 3 days b.d. omeprazole 20 mg and placebo antibiotics (n=25); OMC 10 consisted of 10 days b.d. omeprazole 20 mg, metronidazole 400 mg and clarithromycin 250 mg (n=24). H. pylori was assessed by biopsies for culture and histology pre- and 4-6 weeks after OMC therapy. Metronidazole-resistance and clarithromycin-resistance were assessed by the E-test.
Results: Intention-to-treat-eradication rates were: OMC 4, 96%; OMC 7, 92%; and OMC 10, 96% (N.S.). All of the three per protocol eradication rates were 100% (95% CI: 85.2-100). Of 75 isolates, 16 were metronidazole-resistant and one was clarithromycin-resistant.
Conclusion: In H. pylori-positive ulcer patients, OMC 4 is highly efficacious and as effective as OMC 7 and OMC 10. No influence of metronidazole-resistance or clarithromycin-resistance was observed.