Purpose:Clostridium difficile infection (CDI) is a significant problem which is increasing in incidence and severity in hospitalized patients. While reported in vitro resistance to metronidazole (MTZ) and vancomycin (VAN) is relatively nonexistent, clinical outcomes with these drugs have been less than desirable (Clin Infect Dis 2005;40:1586–90, Clin Infect Dis 2006;43:421–7). Furthermore, the concern of possible selection for VAN resistance has created a need for alternative antibiotic therapies for CDI. Nitazoxanide (NTZ) is a first in class thiazolide indicated for the treatment of diarrhea caused by Cryptosporidium parvum and Giardia lamblia. Previous studies have proven NTZ to be a safe and effective agent for the initial treatment of CDI and in patients who failed MTZ therapy (J Antimicrob Chemother 2007;59:705–10, DDW 2008: Presentation W1272). However, data is limited in patients with renal disease, especially in peritoneal dialysis (PD). Methods: This case report details the successful utilization of NTZ for the treatment of recurrent CDI in a PD patient. Results: The patient is a 58 year old female on PD, admitted to our hospital for the first time with orthostatic hypotension, severe nausea and vomiting attributed to MTZ therapy for CDI. This was her 5th hospital admission in the last 3 months. Previous CDI treatment regimens had included MTZ and combinations of MTZ and VAN. During her admission the patient developed pneumonia that was successfully treated with moxifloxacin (MOX). On day 7 of MOX therapy she developed diarrhea and her stool tested positive for CD toxins A or B. MOX was discontinued and the patient was started on an oral regimen of NTZ 500 mg twice daily and probiotics were added to assist in reestablishing the colonic flora. Within 7 days of initiating NTZ therapy the patient's diarrhea completely resolved and her stools were negative for CD toxins A or B. The patient was subsequently discharged and instructed to complete 6 weeks of therapy. Overall, the regimen was well-tolerated and 4 months after the cessation of therapy the patient had no further recurrences of CDI. Conclusion: NTZ was chosen based on our clinical experience and studies demonstrating its effectiveness in CDI. The overall safety of NTZ is well-established and the pharmacologic characteristics of NTZ are well suited for the treatment of CDI. NTZ appears to be a safe and effective therapy for the treatment of recurrent CDI. Additional studies are warranted to further validate the efficacy of NTZ in CDI in patients with various underlying conditions such as renal failure.