Comparative effectiveness of vancomycin and fidaxomicin in the treatment of Clostridioides difficile–associated diarrhea: A single-center experience in Taiwan

Clostridioides difficile-associated diarrhea (CDAD) has become an increasingly common healthcare-associated infection worldwide. Although both vancomycin and fidaxomicin are approved for treatment, real-world comparative data from Taiwan remain limited. This study aimed to evaluate the effectiveness of vancomycin and fidaxomicin in treating CDAD and to identify patients at risk of treatment failure who may benefit from fecal microbiota transplantation. This single-center retrospective observational study was conducted at Far Eastern Memorial Hospital from January 2018 to August 2020. Adult patients (≥20 years) diagnosed with CDAD and treated with oral vancomycin (125 mg 4 times daily) and/or fidaxomicin (200 mg twice daily) for 10 days were included. Treatment success and failure rates were compared between groups, and associations with age, sex, and Charlson Comorbidity Index (CCI) were analyzed using a Student t test and chi-square test, with significance defined as P ≤ .05. A total of 166 patients were analyzed (mean age = 72.36 ± 14.72 years; mean CCI = 6.80 ± 2.61). Of these, 161 received vancomycin and 48 received fidaxomicin. The treatment success rate was 53.4% for vancomycin and 79.2% for fidaxomicin. Among vancomycin-treated patients, treatment failure was significantly associated with older age (P = .009) and higher CCI (P = .004). No statistically significant associations were observed for fidaxomicin outcomes with age, sex, and CCI. Fidaxomicin demonstrated superior clinical effectiveness to vancomycin, particularly among older adults and patients with multiple comorbidities. These findings support prioritizing fidaxomicin for high-risk patients and considering fecal microbiota transplantation in refractory cases.