Omeprazole-amoxycillin versus omeprazole-amoxycillin-clarithromycin in the eradication of Helicobacter pylori

To assess the effect of adding clarithromycin to the combination of omeprazole and amoxycillin for the eradication of H. pylori infection.

In an open, randomized, three-centre study 120 patients (69 men, mean age 47 years, caucasians 74%) with symptoms of dyspepsia had normal gastroscopic examination and a positive urease test. They underwent a 13C-urea breath test and received, for 14 days, either omeprazole 40 mg b.d. plus amoxycillin 750 mg b.d., or the same regimen plus clarithromycin 250 mg b.d. Compliance was assessed by returned tablet counts. H. pylori clearance at the end of treatment and eradication 4 weeks after finishing treatment were assessed by 13C-urea breath test.

Results are expressed according to 'all patients treated analysis', excluding patients who did not receive treatment and patients who had no final 13C-urea breath test assessment. In the groups treated with omeprazole-amoxycillin or omeprazole-amoxycillin-clarithromycin good compliance (> or = 90%) was observed in 85% vs. 76% (N.S.) of patients but 25% vs. 34% (N.S.) experienced at least one adverse event. Adverse events were minor, and no patient reported a metallic taste. Four weeks after finishing treatment eradication rates were 26% (95% CI: 15-37%) vs. 93% (95% CI: 86-99%) (P < 0.001).

These results show that dual therapy with omeprazole plus amoxycillin achieves an unacceptably low H. pylori eradication rate. Addition of clarithromycin at low dosage (250 mg b.d.) proved to be useful, achieving a high eradication rate without increasing side-effects.