Second-line treatment for Helicobacter pylori infection in Japan: proton pump inhibitor-based amoxicillin and metronidazole regimen.

Background: Recent studies have reported that proton pump inhibitor (PPI)/amoxicillin (A) metronidazole (M) therapy for Helicobacter pylori infection provides a sufficient cure rate in Japan in patients who have failed first-line treatment with PPI/amoxicillin and clarithromycin (AC). To validate the efficacy of this regimen as second-line therapy, our experience with second-line treatment using a PPI/AM regimen was reviewed.
Methods: We analyzed data on 151 patients who had been prescribed a 10-day PPI/AM re-treatment regimen after eradication failure of 1 to 2 weeks' first-line PPI/AC therapy. The PPI/AM regimen was given according to results of susceptibility testing (S+) in 31 patients. The group that had undergone susceptibility testing was further divided into two subgroups according to dosage: standard dose of omeprazole (O)/AM (n = 11) and double dose of lansoprazole (L)/AM (n = 20). The PPI/AM regimen was given without susceptibility testing (S-) to 120 patients. These patients were also divided into two subgroups according to whether they received omeprazole or lansoprazole: OAM (n = 61) and LAM (n = 59). Cure rates and adverse effects in each group were analyzed.
Results: The intention-to-treat (ITT)-based cure rate with/without susceptibility testing was 93.5% (95% confidence interval [CI], 79%-99%) and 87.5% (95% CI, 80%-93%), respectively (not significant [NS]). The ITT-based cure rate in S+/S- for OAM and S+/S- for LAM was 90.9% (95% CI, 59%-100%)/82% (95% CI, 70%-91%), and 95% (95% CI, 75%-100%)/93.2% (95% CI, 84%-98%), respectively (NS). Adverse effects were seen in 26.3% and 32.5% of patients in the OAM group and the LAM group, respectively (NS).
Conclusions: The 10-day PPI/AM re-treatment regimen is safe and effective, suggesting its usefulness as second-line treatment in Japan in patients who have failed initial treatment with the PPI/AC regimen.