One-week proton pump inhibitor-based triple therapy eradicates residual Helicobacter pylori after failed dual therapy

The purposes of this study were to assess the efficacy of a 1-week proton pump inhibitor (PPI)-based triple therapy after failure of dual therapy in Helicobacter pylori eradication, and to compare the effectiveness of clarithromycin and metronidazole in this regimen. Between January 1996 and March 1997, 67 patients with persistent H. pylori infection after a 2-week course of dual therapy (amoxicillin plus omeprazole) were enrolled. They were randomly assigned to receive amoxicillin (1000 mg twice daily) and omeprazole (20 mg twice daily) plus either metronidazole (500 mg twice daily) or clarithromycin (250 mg twice daily). Endoscopy was performed in each patient to assess the status of H. pylori using the rapid urease test (CLOtest) and the histologic findings before dual therapy, after dual therapy, and after triple therapy. H. pylori isolates were tested for antibiotic resistance when triple therapy failed. The 1-week triple therapy was well tolerated in both groups with no adverse effects severe enough to cause withdrawal from the trial. Residual H. pylori was eradicated in 94% (33/35) of patients in the clarithromycin group and 84% (27/32) in the metronidazole group; the difference was not statistically significant. All seven patients in whom triple therapy failed were infected with metronidazole-resistant isolates and two also had clarithromycin-resistant isolates. This 1-week triple therapy is safe and effective in eradicating residual H. pylori after dual therapy failure. Failure of the rescue regimen is related to antimicrobial agent resistance. Because of the high metronidazole resistance rate in Taiwan, clarithromycin appears to be more promising than metronidazole for the control of H. pylori.