A Randomized Clinical Trial Comparing the Efficacy and Tolerability of Two Quadruple Regimens: Bismuth, Omeprazole, Metronidazole with Amoxicillin or Tetracycline as First-Line Treatment for Eradication of Helicobacter Pylori in Patients with Duodenal Ulc

Aim: To evaluate the efficacy and tolerability of replacing tetracycline with high dose of amoxicillin in bismuth-based quadruple therapy for H.pylori eradication. Methods: This randomized, open label clinical trial study was performed on 228 patients with H.pylori infection and duodenal ulcer without the history of previous H.pylori treatment. Patients were randomly divided into two groups. Group one received metronidazole 500mg, bismuth subcitrate 240mg and amoxicillin 1000mg, all three times a day and omeprazole 20 mg twice a day (amoxicillin group)for14 days. The second group received metronidazole 500mg three times a day and bismuth subcitrate240mg and tetracycline HCL 500mg both four times a day and omeprazole 20 mg twice a day (tetracycline group), for 14 days. Evaluation for compliance and drugs side effects were done after two weeks. Eight weeks after treatment, H.pylori eradication rate was assessed by c13-urease breath test. Results: Two hundred twenty-eight patients were enrolled. There was no statistically significant demographic difference between two groups. Amoxicillin containing regimen achieved higher Eradication rate: 105 of 110 ,95.51% (95%CI 91.5% to 99.3%) and 88 of 105, 83.8% (95% CI 76.7% to 90.8%) by per-protocol analysis (p-value=0.005) and 92.9%(95%CI 88.1% to 97.6%) and 76.5% (95% CI 68.7% to 84.2%) by intention-to-treat (p-value=0.001) for amoxicillin and tetracycline groups, respectively. Adverse events were statistically more significant higher in Tetracycline group (65.2%) amoxicillin group (43.4%) (P value = 0.001). Conclusion: Bismuth based quadruple therapy included high dose of amoxicillin and metronidazole has an acceptable H. pylori infection eradication rate with good tolerance in patients with duodenal ulcer. This can overcome treatment resistance in areas with high prevalence of metronidazole and clarithromycin resistance