BACKGROUND AND AIM The aim of this study was to evaluate the efficacy of a moxifloxacin-containing triple therapy as second-line treatment for Helicobacter pylori infection. We also investigated the effect of treatment duration and antibiotic resistance on the eradication rate of this therapy.

METHODS We prospectively enrolled patients found to have persistent H. pylori infections after failure of first-line proton-pump inhibitor-based triple therapy. Patients took moxifloxacin (400 mg q.d.), amoxicillin (1000 mg b.i.d.), and esomeprazole (20 mg b.i.d.). The eradication rate, drug compliance, and adverse event rates were evaluated. Minimal inhibitory tests were performed for moxifloxacin and amoxicillin by the agar dilution method.

RESULTS In 2004, 41 patients were treated for 7 days. The intention-to-treat and per-protocol eradication rates (ITT/PP) were 75.6/83.8%. Moxifloxacin resistance was 5.6%. Therapy was extended to 10 days during 2005-2006 and 139 patients were treated. The ITT/PP eradication rates were 71.9/82.6%; moxifloxacin resistance had increased to 12%. The final group of 181 patients in 2007-2008 who were treated for 14 days also had low eradication rates (68/79.9%), but there was no statistical significance in the efficacy among the treatment periods. Moxifloxacin resistance in 2007-2008 was 28.2%. Side-effect increased with treatment duration (i.e., 9.8, 12.2, and 25.4% at 7, 10, and 14 days, respectively, p = .001).

CONCLUSION The 7-day moxifloxacin-containing triple therapy produced an unacceptably low eradication rate. Increasing the duration of therapy was expected to increase the eradication rate, but the expected increased did not materialize, most likely because of coincident marked increase in the prevalence of resistance to moxifloxacin. Tailored treatment based on antibiotic susceptibility testing might be more effective in the achievement of high eradication rate when rapid antibiotic resistance such as moxifloxacin is occurring.