Retrospective comparison of long-term ten-day/month rifaximin or mesalazine in prevention of relapse in acute diverticulitis.

Diverticular disease (DD) of the colon has an increasing burden on health services. The effectiveness of rifaximin for the treatment of DD, is not yet established. The aim of this study is to assess the impact of long-term treatment with rifaximin or mesalazine in a 10-day schedule for the prevention of recurrent diverticulitis.This is a retrospective study. We identified all consecutive patients with DD and previous acute diverticulitis (AD) in our outpatients' database; 124 patients, were included. The recommended therapy consisted of a ten-day/month treatment with either rifaximin (400 mg bid), or mesalazine (2.4 g/daily). Primary end point was AD recurrence.Between 2010 and 2014, 72 patients were treated with rifaximin and 52 with mesalazine. During a median follow-up of 15 months (range 1-50), we observed 21 episodes of AD among users of either rifaximin (n=7; 0.54 per 100 person-months), or mesalazine group (n=14; 1.46 per 100 person-months). Kaplan-Meier survival estimates of recurrent AD significantly differed between rifaximin and mesalazine groups (p=0.015). The multivariate Cox regression analysis showed that AD recurrence was significantly associated with therapy (rifaximin vs. mesalazine, adjusted HR 0.27; 95% CI: 0.10 to 0.72), age and gender.Long-term treatment with rifaximin in a 10-day schedule appears more effective than mesalazine in preventing recurrent AD.