Improved efficacy of proton pump inhibitor - amoxicillin - clarithromycin triple therapy for Helicobacter pylori eradication in low clarithromycin resistance areas or for tailored therapy.

Objective: Standard triple therapy for Helicobacter pylori eradication is no longer effective as an empiric choice in most areas. Even in low clarithromycin resistance areas, results ≥95% are infrequently achieved. This study was designed to search for a version of standard triple therapy for use low prevalence areas or as tailored therapy that is highly effective irrespective of CYP2C19 genotype.
Design: Two prospective pilot single center studies were performed in Thailand. H. pylori-infected subjects were randomized to 7- or 14-day regimens using a high-dose proton pump inhibitor (PPI) triple therapy consisting of lansoprazole (60 mg) twice daily, amoxicillin 1 g twice daily, and long-acting clarithromycin MR 1 g once daily. H. pylori was defined as positive H. pylori culture; or two positive tests (rapid urease test and histology); CYP2C19 genotyping was performed. H. pylori eradication was evaluated by (13) C-UBT 4 or more weeks after treatment.
Results: Hundred and ten subjects were enrolled (55 each to the 7- and 14-day regimens). Antibiotic susceptibility testing (25 strains) showed 40% metronidazole resistance but no clarithromycin resistance. CYP2C19 genotyping (64 subjects) revealed 56.3% rapid metabolizer, 29.7% intermediate metabolizer, and 14% poor metabolizer. The eradication rate with the 14-day regimen was 100% (95% CI = 93.5-100%) and 92.7% (95% CI = 82-97%) with the 7-day regimen. The difference was related to improved eradication at 14 days in rapid metabolizers (i.e. 100 vs 88.2%).
Conclusion: Triple therapy using a 14-day high-dose PPI and long-acting clarithromycin provided an excellent cure rate (100%) regardless of the CYP2C19 genotype.
(© 2013 John Wiley & Sons Ltd.)