7-day rescue therapy with ranitidine bismuth citrate after Helicobacter pylori treatment failure

BACKGROUND: Quadruple rescue therapy requires a complex scheme with four drugs. AIM: To evaluate the efficacy of ranitidine bismuth citrate-tetracycline-metronidazole rescue regimen, and to compare two different metronidazole dose schemes. METHODS: Prospective multicentre study including proton-pump inhibitor + clarithromycin + amoxicillin failures. Rescue regimen included two 7-day treatment: (i) ranitidine bismuth citrate (400 mg b.d.)-tetracycline (500 mg q.d.s.)-metronidazole (500 mg t.d.s.; RTM1); or (ii) the same regimen but with metronidazole 250 mg q.d.s. (RTM2). Eradication was confirmed with (13)C-urea breath test. RESULTS: A total of 150 patients were included (58 RTM1, 92 RTM2). All patients but two (one in each group) returned after treatment. About 86% in group RTM1 and 95% in RTM2 correctly took all the medications (P = 0.076). Per-protocol eradication rates with RTM1 and RTM2 were 74 (95% CI: 60-84) and 69% (59-78). The intention-to-treat eradication rates were 64 (51-75) and 70% (59-78; P > 0.05). The type of regimen was not associated with eradication in the multivariate analysis. Adverse effects were more frequent with RTM1 (41%) than with RTM2 (30%; P > 0.05). CONCLUSION: Seven-day triple rescue therapy with ranitidine bismuth citrate-tetracycline-metronidazole is effective for Helicobacter pylori eradication, and represents an encouraging alternative to quadruple therapy, with the advantage of simplicity. The administration of metronidazole every 6 h (together with tetracycline), and at a low dose (250 mg), achieves similar efficacy and is probably associated with a better compliance and a lower incidence of adverse effects.