Efficacy of Bismuth-Containing Quadruple Therapies for Clarithromycin-, Metronidazole-, and Fluoroquinolone-Resistant Helicobacter pylori Infections in a Prospective Study

BACKGROUND & AIMS: We assessed the efficacy and safety of 4 bismuth-containing quadruple regimens as empiric therapies for Helicobacter pylori infections in patients who did not respond to previous treatment. METHODS: We performed a prospective single-center study of 424 patients with H pylori infection that was not eradicated by previous therapies. Patients were assigned randomly to groups given lansoprazole (30 mg twice daily) and bismuth potassium citrate (220 mg twice daily), along with 500 mg tetracycline and 400 mg metronidazole 4 times daily (LBTM), 500 mg tetracycline and 100 mg furazolidone 3 times daily (LBTF), 1000 mg amoxicillin 3 times and 500 mg tetracycline 4 times daily (LBAT), or 1000 mg amoxicillin and 100 mg furazolidone 3 times daily (LBAF). Eradication was assessed by a C-13-urea breath test. Antimicrobial susceptibility was assessed in 188 patients by the agar dilution method. RESULTS: Per-protocol rates of H pylori eradication were greater than 90% for all regimens: 93.1% for LBTM (95% confidence interval [CI], 88.1%-98.0%), 96.1% for LBTF (95% CI, 92.4%-99.8%), 94.6% for LBAT (95% CI, 90.0%-99.2%), and 99.0% for LBAF (95% CI, 97.0%-100%). The intention-to-treat response rates were 87.9% for LBTM (95% CI, 81.7%-94.0%), 91.7% for LBTF (95% CI, 87.1%-96.3%), 83.8% for LBAT (95% CI, 76.8%-90.9%), and 95.2% for LBAF (95% CI, 91.1%-99.3%). Significantly more patients had infections eradicated by furazolidone-containing regimens than nonfurazolidone regimens (P = .01). Side effects occurred in 33.6% of subjects and occurred significantly more frequently in the LBTM group than the other 3 groups (vs LBTF, P = .006; vs LBAT, P = .003; vs LBAF, P = .02). Metronidazole resistance was 96.8%; no isolates were resistant to amoxicillin, tetracycline, or furazolidone. CONCLUSIONS: Four bismuth-containing quadruple therapies achieved greater than 90% eradication of H pylori in patients who did not respond to previous treatment, including patients with metronidazole resistance. For patients allergic to penicillin, tetracycline and either metronidazole-or furazolidone-containing regimens are recommended.