Objective: Recent randomized control trials (RCTs), have demonstrated the beneficial therapeutic effects of rifaximin for the treatment of the irritable bowel syndrome (IBS). However, in these studies different drug doses have been used and still the optimal therapeutic dose is missing. We aimed to determine rifaximin therapeutic benefit and optimal dose for IBS as evidenced by the results of a network meta-analysis (NWM) of published randomized controlled trials (RCTs).

Materials and Methods: PubMed/MEDLINE, EMBASE, and Cochrane Library databases were searched for RCTs investigating the therapeutic effects of rifaximin on IBS through December 2019. Data from each selected RCT were evaluated individually based on an intention-to-treat analysis. A Bayesian NWM was performed to investigate the efficacy rank order of rifaximin therapeutic interventions in IBS.

Results: Four eligible studies, including 5 sets of data, were included in this NWM. They included 1,803 IBS patients, randomized to placebo (908 patients), and rifaximin (895 patients). In patients who received rifaximin, four regimens were examined, i.e., (A) = 400 mg tds for 10 days, (B) = 400 mg bid for 10 days, (C) = 550 mg bid for 2 weeks and (D) = 550 mg tds for 2 weeks. The results showed that in IBS rifaximin 400 mg tid for 10 days showed the highest efficacy [SUCRA (surface under cumulative ranking) value 89.5%], in comparison to other rifaximin regimens used and placebo.

Conclusions: This NWM showed that the therapeutic efficacy of rifaximin 400 mg tid in IBS patients was greater than that of placebo and the other rifaximin doses studied.