Gatifloxacin-based triple therapy as a third-line regimen for Helicobacter pylori eradication

Background and Aim: This study was designed to investigate the efficacy of gatifloxacin (GAT)-based triple therapy as a third-line treatment for Helicobacter pylori (H. pylori) eradication, according to the assessment of the susceptibility to GAT and gyrA mutation. Methods: Fourteen patients who had eradication failure following both clarithromycin-based triple therapy and metronidazole-based triple therapy, or who were infected with H. pylori isolates that were resistant to both clarithromycin and metronidazole after failure of clarithromycin-based triple therapy, were enrolled. These patients were randomly assigned to two groups: (i) rabeprazole and amoxicillin (RA) and (ii) rabeprazole, amoxicillin, and GAT for 7 days (RAG). The minimal inhibitory concentrations were determined by the agar dilution method. The gyrA gene was examined by sequencing. Results: The eradication rate was 0% in the RA group and 75% in the RAG group. The eradication rate in the RAG group was 100% in patients infected with GAT-susceptible bacteria and/or bacteria without gyrA mutations, but was only 33.3% in those infected with GAT-resistant bacteria or bacteria with gyrA mutations. Conclusion: Although GAT may be a promising candidate for third-line therapy, its selection must be based on the results of drug susceptibility testing or gyrA analyses.