Addition of bismuth to standard triple therapy for Helicobacter pylori eradication: a randomised controlled trial

OBJECTIVE: To compare the effect of addition of bismuth to the standard triple therapy for eradication of Helicobacter pylori (H. pylori) in a randomised controlled trial. METHODS: The study was performed from June 2018-May 2019, in the two outpatient departments located at two different campuses of Ziauddin university hospitals (ZUH) Karachi. Ethical approval was obtained from the Ethics Review Committee of ZUH. It was designed as a randomized control trial in a parallel fashion. Arm A received triple therapy including amoxicillin, clarithromycin, and omeprazole for two weeks and Arm B received quadruple therapy adding colloidal bismuth subcitrate to the triple therapy. A stool antigen test was done six weeks post treatment to confirm H. pylori eradication. RESULTS: A total of 196 participants were included, out of which 102(52%) were males and 94 (48%) were females. Among the patients receiving quadruple therapy, 92/98(93.8%) had negative posttreatment stool antigen results, while among triple therapy recipients 83/98 (84.6%) had negative stool antigen results, according to intention-to-treat analysis (p value=0.038; odds ratio 2.77, 95% CI 1.03-7.47). However, p-value changed to 0.082 (odds ratio 2.40, 95% CI 0.87-6.60) in per-protocol analysis as stool antigen results were not available in two patients in the triple therapy arm. No difference in the side-effect profiles of either arm was noted. CONCLUSIONS: Eradication rates of H. pylori may be modestly improved by addition of bismuth to the standard triple therapy. Clinical Trial Number: 03968302 (clinicaltrials.gov).