AIM: To determine the efficacy of two quintupleregimens for eradication of Helicobacter pylori(H. pylori) in patients who failed previous therapies.METHODS: This prospective, open-label, randomized controlled trial was a phase Ⅱ study conducted from April 2011 to March 2012 at the Gastrointestinal and Liver Diseases Research Center in Rasht, Iran. A total of 208 patients with dyspepsia who failed previous H. pylori eradication with a ten-day quadruple therapy were enrolled. A random block method was used to assign patients to one of two treatment groups. Patients in the first group were treated with 240 mg bismuth subcitrate, 20 mg omeprazole, 1000 mg amoxicillin, 500 mg clarithromycin and 500 mg tinidazole(BOACT group). Patients in the second group received a regimen containing 240 mg bismuth subcitrate, 20 mg omeprazole, 500 mg tetracycline, 500 mg metronidazole and 200 mg ofloxacin(BOTMO group). Both regimens were given twice daily for a duration of seven days. The eradication was confirmed by a 14 C urea breath test 12 wk after completion of therapy. Patient compliance and drug side effects were evaluated at the end of the treatment period. The success rates were calculated by intention-to-treat and per-protocol analyses.RESULTS: A total of 205 patients completed the course of treatment, with three patients excluded due to drug intolerance. The mean age of patients did not differ between the BOACT and BOTMO groups(41.6 ± 12.2 years vs 39.6 ± 11.8 years), and no significant differences were found between the two groups in terms of age, sex, smoking habits or the initial eradication regimen. The intention-to-treat and perprotocol eradication rates were significantly higher in the BOTMO group(86.5%, 95%CI: 0.85-0.87 and 86.7%, 95%CI: 0.80-0.89, respectively) compared with the BOACT group(75.5%, 95%CI: 0.73-0.76 and 76%, 95%CI: 0.69-0.80, respectively)(P < 0.05). Univariate analyses for both groups did not show any association of sex, smoking and initial therapeutic regimen witheradiation rate(P > 0.05 for all). Significantly more patients experienced side effects in the BOACT group compared to the BOTMO group(77.4% vs 36.6%, P < 0.01). This difference was exemplified by increases in headache and taste disturbance(P < 0.05).CONCLUSION: Quintuple therapy with a BOTMO regimen is an alternative second-line rescue therapy for Iranian patients with failed first-line eradication treatment of H. pylori. AIM: To determine the efficacy of two quintupleregimens for eradication of Helicobacter pylori (H. pylori) in patients who failed previous therapies. METHODS: This prospective, open-label, randomized controlled trial was a phase Ⅱ study conducted from April 2011 to March 2012 at the Gastrointestinal and Liver Diseases Research Center in Rasht, Iran. A total of 208 patients with dyspepsia who failed previous H. pylori eradication with a ten-day quadruple therapy were enrolled. A random block method was used to assign patients to one of two Patients in the first group were treated with 240 mg bismuth subcitrate, 20 mg omeprazole, 1000 mg amoxicillin, 500 mg clarithromycin and 500 mg tinidazole (BOACT group). Patients in the second group received 240 mg bismuth subcitrate, 20 mg omeprazole, 500 mg tetracycline, 500 mg metronidazole and 200 mg ofloxacin (BOTMO group). Both regimens were given twice daily for a duration of seven days. The eradication was confirmed by a 14 C urea breath test 12 wk after completion of therapy. Patient compliance and drug side effects were evaluated at the end of the treatment period. The success rates were calculated by intention-to-treat and per-protocol analyzes .RESULTS: The total age of patients did not differ between the BOACT and BOTMO groups (41.6 ± 12.2 years vs 39.6 ± 11.8 years), and no significant differences were found between the two groups in terms of age, sex, smoking habits or the initial eradication regimen. The intention-to-treat and perprotocol eradication rates were significantly higher in the BOTMO group (86.5%, 95% CI: 0.85-0.87 and (75.5%, 95% CI: 0.73-0.76 and 76%, 95% CI: 0.69-0.80, respectively) (P <0.05). Univariate analyses for both groups did not show any association of sex, smoking and initial therape uticSignificantly more patients experienced side effects in the BOACT group compared to the BOTMO group (77.4% vs 36.6%, P <0.01). This difference was graph by increases in headache and taste disturbance ( P <0.05). CONCLUSION: Quintuple therapy with a BOTMO regimen is an alternative second-line rescue therapy for Iranian patients with failed first-line eradication treatment of H. pylori.