Outcomes with Fidaxomicin Therapy in Clostridium difficile Infection

Background and Goals: Fidaxomicin is a new antibiotic used to treat Clostridium difficile infection (CDI). Given limited clinical experience with fidaxomicin, we assessed outcomes in a diverse cohort of patients with CDI treated with fidaxomicin. Study: All CDI cases treated with fidaxomicin at 3 referral centers over a 4-year period were included. Response was defined as resolution of diarrhea and recurrence was defined by recurrence of CDI within 8 weeks of the end of treatment. Results: Overall, 81 patients (median age 55.9 y; 53% female; 26% with inflammatory bowel disease) were included. Response occurred in 90%. Responders had fewer prior CDI episodes [median 1 (range, 0 to 8)] than nonresponders [median 2.5 (range, 1 to 8)], P=0.01. Response after a first CDI episode was 100%, 96% after 1 prior episode, and 82% after 2 or more, P=0.02. Recurrence occurred in 19%. Patients without recurrence had fewer prior episodes of CDI [median 1 (range, 0 to 6)] than patients who recurred [median 2 (range, 1 to 8)], P=0.005. Recurrence after a first episode was 0%, 23% after 1 prior episode, and 29% after 2 or more, P=0.005. All patients with inflammatory bowel disease responded either with improvement of symptoms or a negative C. difficile test; 19% recurred. Conclusions: All patients with a first CDI episode treated with fidaxomicin responded with no recurrences. Patients with prior CDI episodes were less likely to respond (especially with more than 1 prior episode) and more likely to recur, suggesting a greater clinical benefit of fidaxomicin earlier in the course of CDI.