Rifaximin in the treatment of recurrent Clostridium difficile infection

Background Clostridium difficile can cause severe antibiotic-associated colitis. Conventional treatments with metronidazole and vancomycin improve symptoms, but after discontinuation of treatment, C. difficile infection (CDI) recurs in a number of patients. Rifaximin is a rifamycin-based non-systemic antibiotic that has effect against C. difficile. Aim To assess the effectiveness of rifaximin in recurrent C. difficile infection. Methods We retrospectively evaluated the records of 32 patients who were treated with rifaximin for recurrent C. difficile infection. The symptoms were evaluated 12 weeks after the start of treatment and patient records were followed up until 1 year after treatment. Results The mean age of the patients was 55 years (median 64, range: 1984 years). Before the initiation of rifaximin therapy, the patients had undergone, on the average, 4.4 (range: 212) antimicrobial courses for C. difficile infection. C. difficile strain typing was performed in 27 patients. Eight (30%) patients had a strain with a DNA profile compatible with the BI/NAP1/027 ribotype. Antibiotic susceptibilities were determined of isolates from 22 patients. Most isolates (68%) had very low MIC-values for rifampin (<0.002 mu g/mL) and the highest MIC value was 3.0 mu g/mL. Isolates with a DNA profile compatible with the BI/NAP1/027 ribotype had, on the average, higher MICs of rifampin. After 12 weeks 17 (53%) patients had no relapse. The MIC value of rifampin seemed to predict the response to rifaximin treatment. Conclusions Rifaximin is a safe treatment for C. difficile infection. It has a reasonable effect in C. difficile infection and it can be considered as an optional treatment for recurrent C. difficile infection.