Fidaxomicin versus oral vancomycin for infection among patients at high risk for recurrence based on real-world experience.

Introduction: infection (CDI) is a common nosocomial infection and is associated with a high healthcare burden due to high rates of recurrence. In 2021 the IDSA/SHEA guideline update recommended fidaxomicin (FDX) as first-line therapy. Our medical center updated our institutional guidelines to follow these recommendations, prioritizing FDX use among patients at high risk for recurrent CDI (rCDI).

Methods: This pre- post- quasi-experimental study included patients with a presumptive diagnosis of CDI at risk for recurrence (age >/= 65 years, immunocompromised, severe CDI) that received vancomycin (VAN) or FDX between October 2019 to October 2022. Patients who received bezlotoxumab, had fulminant CDI, or received <10 days of the same antibiotic for their full treatment course were excluded. Patients were evaluated for rCDI within 8 weeks of completion of therapy, subsequent episodes of CDI within 12 months, and CDI-related admissions within 30 days.

Results: Of 397 CDI regimens evaluated, 196 received VAN and 201 received FDX. Rates of rCDI (9.2% vs 10%, = 0.86), subsequent CDI within 12 months of therapy completion of therapy (19.4% vs 26%, = 0.12) and 30-day CDI-related readmissions (3% vs 4.5%, = 0.6) were similar between patients who received VAN versus FDX.

Conclusion: Outcomes were similar between patients treated with FDX and VAN for the treatment of CDI among those at high risk for rCDI, using our outlined criteria. Although we observed a trend toward lower rates of rCDI among immunocompromised patients, this finding was not significant. Further investigation is needed to determine which patients with CDI may benefit from FDX.