A randomised trial of amoxycillin versus clarithromycin in combination with omeprazole for eradication of Helicobacter pylori infection in Singapore

Dual therapy has been reported to produce H.pylori eradication rate of 75-80%. This study is designed to determine the efficacy of omeprazole 20 mg bd in combination with amoxycillin 500 mg tid (Group A), amoxycillin 750 mg tds (Group B) and clarithromycin 500 mg tid (Group C) in Singapore. One hundred and forty-eight patients with H. pylori positive duodenal ulcers between ages of 22 and 69 were enrolled from two centres. There were 48 patients in Group A, 50 patients in Group B and 50 patients in Group C. The medication was given for 14 days. The patients were re-evaluated with an upper GI endoscope 4 weeks after cessation of treatment Successful eradication was defined as H.pylori negative on histology and culture. Based on intention to treat analysis, the eradication rate was 47.8% in Group A, 68% in Group B and 66% in Group C. The difference between GroupA and B were statistically significant (p = 0.04). Based on all patient treated analysis, the eradication rate was 57.5% in Group A, 70.7% in Group B and 75% in Group C. The difference in eradication rates was not statistically significant. Adverse events were reported in 21% of all patients with no difference in the adverse event rate between all groups. The eradication rate achieved with dual therapy in this study was similar to that attained in Western population. Higher dose amoxycillin regime gives a significantly higher eradication than a lower dose amoxycillin.