Nitazoxanide is active against Clostridium difficile strains with reduced susceptibility to metronidazole

Treatment strategies for Clostridium difficile infection (CDI) have changed little over the past two decades. Metronidazole and vancomycin continue to be the first-line antimicrobial treatments for CDI.1 While the drugs were thought to be similar in terms of response and recurrence rates, recent reports suggest that metronidazole efficacy may be reducing.2,3 A study of 52 patients by Al-Nassir et al.3 showed that while diarrhoea resolved in a majority of patients (>90%) treated with either metronidazole or vancomycin, the former was associated with a slower and less consistent microbiological response. In addition, poor gut levels of metronidazole and emerging evidence of reduced susceptibility in epidemic C. difficile strains, particularly among epidemic C. difficile PCR ribotypes,4 may play a role in reduced antibiotic efficacy. These issues highlight the need for effective new treatments for CDI