Rifaximin and Treatment of Recurrent Clostridium difficile Infection in Patients with Inflammatory Bowel Disease: 1206

Purpose: Clostridium difficile (C. difficile) is increasing in North American medical centers and can negatively impact clinical course in patients with inflammatory bowel disease (IBD; Crohn's disease, ulcerative colitis). Recent reports suggest a 50% failure rate with metronidizole therapy for C. difficile, while vancomycin is associated with high recurrence rates (DM Musher et al. Clin Infect Dis. 2005;40:1586–90). Rifaximin (Xifaxan, Salix Pharmaceuticals, Raleigh, NC) is a non-absorbable oral antibiotic which has efficacy against C. difficile. We examined rates of recurring C. difficile infection encountered in a cohort of IBD patients and specifically focused on patients with recurrent infection and those who required rifaximin treatment. Methods: This was a retrospective, observational study of IBD patients diagnosed with C. difficile (positive stool ELISA toxin A, B) in a single tertiary referral center during 2005. Initial and recurrent treatment for C.difficile was recorded. Recurrence was defined clinically as a relapse after inital resolution of symptoms which required a 2nd course of antibiotics within 2 weeks after initial therapy with metronidazole or vancomycin. Rifaximin was administered for recurrent C. difficile infection on a scheduled taper consisting of 200mg TID × 2 wks, 200 mg BID × 2 wks, 200 mg QD × 2wks and 200 mg qod × 2 wks. Results: A total of 46 out of 999 IBD patients (4.6%) tested positive for C. difficile during 2005. Fifty-eight percent (27/46) required treatment for recurrent infection. These included 17 Crohn's disease and 10 ulcerative colitis patients. All relapsing patients had initially received vancomycin. Among patients with recurrent infection, 52% (14/27) received a rifaximin taper. Colectomy was required in 15% of the C. difficile infected IBD patients (7/46). Two of these patients had experienced recurrent infection. Rifaximin taper was successful for treatment of relapsing infection in all cases. Conclusions: Among IBD pts infected with C. difficile, relapse is frequently encountered in over half of cases. Vancomycin was assosicated with C. difficile relapse in all cases. A prolonged rifaximin taper over an 8 week period was successful in all relapsing cases. Prospective evaluation of rifaximin in C.difficile infected IBD patients, including those experiencing relapse is warranted.