A Retrospective Study of Cefiderocol Utilization and Associated Outcomes at an Academic Medical Center.

Background: This study aimed to describe cefiderocol prescription and associated patient outcomes at a U.S. academic medical center for various multidrug-resistant organisms (MDRO). Notably, limited real-world data exist on cefiderocol's clinical use in regions where metallo-β-lactamase (MBL)-producing organisms are prevalent.

Methods: A retrospective chart review was conducted on adult inpatients who received ≥24 h of cefiderocol between January 2023 and July 2024. Data collected included microbiology, carbapenemase type (CARBA-5), treatment indication, susceptibility profiles, and clinical outcomes: 30-day mortality, re-infection, and re-admission. Descriptive statistics were used.

Results: Seventy-six patients were included, with most receiving cefiderocol for carbapenem-resistant Enterobacterales (CRE) (63%) or P. aeruginosa (17%) infections. Overall, 96% of cases met institutional prescribing criteria. NDM was the predominant carbapenemase (77% of CRE isolates). Cefiderocol was used definitively in 68% of cases. The median duration of therapy was 7 days. Thirty-day mortality was 20%, highest among patients with A. baumannii complex (33%). Re-infection and re-admission occurred in 21% and 32% of patients, respectively. Susceptibility to cefiderocol was highest for P. aeruginosa (100%), Stenotrophomonas (100%), and CRE (88%), but only 50% for A. baumannii complex.

Conclusions: Cefiderocol was primarily used in accordance with institutional criteria and demonstrated favorable susceptibility against most target pathogens. However, poor outcomes in A. baumannii complex infections highlight the need for cautious use and the need for rapid diagnostics for early targeted therapy in multidrug-resistant infections.