Modified bismuth quadruple therapy with low-dose metronidazole as first-line therapy for Helicobacter pylori infection.

BACKGROUND: Bismuth-containing quadruple therapy is an effective alternative first-line therapy for Helicobacter pylori infection. We evaluated the efficacy and safety of a modified twice-a-day bismuth quadruple regimen (BQT-2) with low-dose (1000 mg total) metronidazole as first-line therapy for the eradication of H pylori. MATERIALS AND METHODS: In this prospective pilot study, patients diagnosed with H pylori infection and naïve to eradication therapy were included. The modified BQT-2 therapy consisted of rabeprazole 20 mg, amoxicillin 1 g, metronidazole 500 mg, and tripotassium dicitrato bismuthate 600 mg (elemental bismuth 240 mg) twice daily, given 30 minutes before morning and evening meals for 14 days. H pylori eradication was assessed by 13 C-urea breath test conducted at least 4 weeks after therapy completion. RESULTS: In 66 patients who received the modified BQT-2 regimen, the compliance rate was 100% and the H pylori eradication rate was 77.3%. H pylori was successfully cultured in 50 (75.8%) patients. The resistance rates to metronidazole and clarithromycin were 30.0% and 22.0%, respectively. Eradication rates were not significantly different according to the resistance to metronidazole (metronidazole-susceptible: 74.3% [26/35], metronidazole-resistant: 73.3% [11/15]; P > .99). Most of the adverse events were mild, with 20 (30%) patients developing nausea, epigastric soreness, loose stool, asthenia, skin rash, dizziness, taste perversion, headache, or dyspepsia. CONCLUSIONS: Twice-a-day modified BQT-2 regimen with low-dose metronidazole was suboptimal as an alternative first-line therapy for eradicating H pylori, despite high patient compliance.