Effectiveness and safety of repeated quadruple therapy in Helicobacter pylori infection after failure of second-line quadruple therapy: repeated quadruple therapy as a third-line therapy

Backgrounds: Quadruple therapy using a proton‐pump inhibitor, bismuth, metronidazole, and tetracycline is a standard second‐line therapy for Helicobacter pylori infection, achieving an eradication rate of about 80% in Korea. A standard third‐line therapy is not currently established, although various protocols have been proposed. We performed this study to evaluate the effectiveness of a retrial with quadruple therapy before starting a third‐line treatment with new drugs. Materials and Methods: In 80 of 746 patients treated with a second‐line quadruple therapy at the Korea University Ansan Hospital between January 2002 and September 2010, treatment for H. pylori had failed, and 45 of these patients were eligible for this study. Eradication of H. pylori was assessed by repeated endoscopy or by the ¹³C‐urea breath test at least 4 weeks after therapy. The patients with treatment failure were treated again with quadruple regimen for 2 weeks and reevaluated for treatment effectiveness and safety. Results: The eradication rate with second‐line quadruple therapy was 86.9%. Of the 80 patients who failed treatment for H. pylori with the initial second‐line quadruple therapy, 64 patients were treated again with the same regimen. Of the 45 retreated patients in this study, three patients were lost to follow‐up and two complied poorly with medication. The eradication rate in the 40 patients retreated was 75.0% at per‐protocol analysis. Seventeen patients experienced mild adverse events. Conclusions: A retrial of quadruple therapy before use of a third‐line therapy may be safe and effective for patients who fail to respond to second‐line quadruple therapy.