Minocycline vs. tetracycline in bismuth-containing quadruple therapy for Helicobacter pylori rescue treatment: a multicentre, randomized controlled trial

Background To compare the efficacy and tolerability of minocycline vs. tetracycline in bismuth-containing quadruple therapy for Helicobacter pylori ( H. pylori ) rescue treatment. Methods This study was a multi-center, randomized-controlled, non-inferiority trial. Refractory H. pylori -infected subjects with multiple treatment-failure were randomly (1:1) allocated to receive 14-day therapy with esomeprazole 20 mg b.i.d, bismuth 220 mg b.i.d, plus metronidazole 400 mg q.i.d and minocycline 100 mg b.i.d (minocycline group) or tetracycline 500 mg q.i.d (tetracycline group). Primary outcome was H. pylori eradication rate evaluated by 13 C-urea breath test at least 6 weeks after the end of treatment. Antibiotic resistance was determined using E test method. Results Three hundred and sixty-eight subjects were randomized. The eradication rates in minocycline group and tetracycline group were 88.0% (162/184, 95% CI 83.3–92.8%) and 88.6% (163/184, 95% CI 83.9–93.2%) in intention-to-treat analysis, 98.0% (149/152, 95% CI 95.8–100%) and 97.4% (150/154, 95% CI 94.9–99.9%) in per-protocol analysis, 93.1% (162/174, 95% CI 89.3–96.9%) and 93.1% (163/175, 95% CI 89.4–96.9%) in modified intention-to-treat analysis. Minocycline, tetracycline and metronidazole resistance rates were 0.7%, 1.4% and 89.6%, respectively. Non-inferiority of minocycline was confirmed ( P < 0.025). Metronidazole resistance did not affect the efficacy of either therapy. The two therapies exhibited comparable frequencies of adverse events (55.4% vs. 53.3%); almost half of them were mild. Dizziness was the most common adverse events in the minocycline group. Conclusions Minocycline can be an alternative for tetracycline in bismuth-containing quadruple therapy for H. pylori empirical rescue treatment, irrespective of metronidazole resistance. However, relatively high incidence of adverse events in both regimens should be emphasized.