A randomized, double-blind, placebo-controlled pilot study to assess the ability of rifaximin to prevent recurrent diarrhoea in patients with Clostridium difficile infection

Background: Uncontrolled case series have demonstrated decreased Clostridium difficile infection (CDI) recurrence in patients given rifaximin after standard antibiotic therapy. However, clinical trials assessing whether rifaximin decreases recurrent diarrhoea in patients with CDI have not been performed. The purpose of this study was to assess rates of recurrent diarrhoea in patients with CDI given rifaximin versus placebo immediately after standard therapy. Methods: This was a randomized, double-blind, placebo-controlled pilot study. Patients with CDI and a Horn's index >= 1 were randomized to receive rifaximin 400 mg three times daily or placebo for 20 days given immediately after finishing standard anti-CDI antibiotics. Patients were followed for 3 months and assessed for recurrent diarrhoea that included CDI recurrence (return of diarrhoea with a positive toxin test) and patient self-reported return of non-CDI diarrhoea after a period of wellness. Results: Sixty-eight patients aged 61 +/- 18 years (50% male) were given rifaximin (n = 33) or placebo (n = 35). Twenty-four of 68 (35%) patients had recurrent diarrhoea either due to recurrent CDI (23.5%) or self-reported diarrhoea (11.5%). Recurrent diarrhoea occurred in 17 of 35 (49%) patients given placebo and 7 of 33 (21%) given rifaximin (P = 0.018). CDI recurrence occurred in 11 of 35 (31%) patients given placebo and 5 of 33 (15%) patients given rifaximin (P = 0.11). Self-reported diarrhoea occurred in 6 of 35 (17%) of patients given placebo and 2 of 33 (6%) given rifaximin (P = 0.15). Conclusions: Patients with CDI given a rifaximin chaser regimen experienced a decreased incidence of recurrent diarrhoea compared with placebo.