Real-world effectiveness of fidaxomicin in patients at high risk of Clostridioides difficile recurrence.

Objective: Compare the real-world impact of fidaxomicin (FDX) and vancomycin (VAN) on Clostridioides difficile infection (CDI) recurrence in a high-risk patient population.

Design: A retrospective, matched-cohort study evaluating hospitalized patients with CDI from January 1, 2016, to November 1, 2022, within a tertiary academic medical center.

Patients: Adult patients with at least 1 prior CDI case who received either FDX or VAN for non-fulminant CDI while admitted, and had at least 1 additional risk factor for recurrence. Risk factors included age >70, solid organ or bone marrow transplant recipients, broad-spectrum antibiotic use within 30 days, or receipt of chemotherapy/immune-modulating agents within 30 days of admission. FDX and VAN patients were matched according to risk factors.

Results: A total of 415 patient admissions were identified. After the exclusion of 92 patients for fulminant CDI, diarrhea from another cause, or use of VAN taper therapy, and 15 unmatched patients, 308 patient admissions were included (68 FDX and 240 VAN patients). There were no significant differences in 4-week recurrence (26% vs 23%; OR 1.1; P = .51), 90-day CDI readmission (29% vs 23%; P = .65), or 90-day all-cause readmission (54% vs 53%; P = .91). There was a significant 17% decrease in 90-day mortality associated with the use of FDX (OR .3; P = .04).

Conclusions: In a real-world high-risk patient population, the use of FDX compared to oral VAN did not result in decreased CDI recurrence within 4 weeks or fewer hospital readmissions within 90 days. Further research is needed to better assess the value of FDX in this patient population.