Comparison of the efficacy of 250 mg and 500 mg clarithromycin used with lansoprazole and amoxicillin in eradication regimens for Helicobacter pylori infection

Aims and methods: The aim of this study was to compare the efficacy of 250 mg and 500 mg clarithromycin used with lansoprazole and amoxicillin in eradication of H. pylori infection. 235 patients with H. pylori infections and non-ulcer dyspepsia were randomly assigned to one of the following regimens: lansoprazole 30 mg, amoxicillin 1000 mg, clarithromycin 250 mg (LAC250) and lansoprazole 30 mg, amoxicillin 1000 mg, clarithromycin 500 mg (LAC500). All drugs were given twice daily for 7 days. The patients were assessed for prevalence of H. pylori with the CLO test. Gastric biopsy samples obtained during upper gastrointestinal endoscopy before randomization and 4-6 weeks after completion of therapy were used for histology and culture. Bacterial sensitivity to clarithromycin and amoxicillin was determined with the E-test. Results: 101 patients in the LAC250 mg group and 102 in the LAC500 group completed the study. On intention-to-treat analysis, eradication rates were 81% with LAC250 and 82% with LAC500 (p = 0.88). On per-protocol analysis, eradication rates were 92% with LAC250 and 96% with LAC500 (p = 0.23). Among the 203 patients (86% of the entire study group) for whom H. pylon anti biotic-sensitivity testing was technically feasible, primary resistance to clarithromycin was found in 9% and to amoxicillin in 0%. Eradication of clarithromycin sensitive/resistant strains was 94%/38% for LAC250 (p < 0.001) and 93%/40% for LAC500 (p < 0.001). Conclusions: The cure rates for the two regimens were similar, although adverse effects were more frequent with the LAC500 regimen, suggesting that 250 mg of clarithromycin b.d. may be sufficient in our patient population.