Ceftazidime-Avibactam for the Treatment of Carbapenem-Resistant Klebsiella Pneumoniae Infection: A Retrospective, Single Center Study.

Purpose: Ceftazidime-avibactam (CZA), a novel beta-lactam/beta-lactamase inhibitor, plays an important role in the threat of emerging carbapenem-resistant Enterobacterales (CRE) infection. The study aims to analyze the clinical effectiveness and factors influencing treatment response to CZA for carbapenem-resistant Klebsiella pneumoniae (CRKP) infections.

Patients and methods: From February 2020 to December 2021, patients with CRKP infection treated with CZA were enrolled in this retrospective, single-center cohort study in northern Taiwan. The primary outcome was 28-day survival rate. The secondary outcomes were clinical success, and microbiological cure. Multivariate regression analysis was used to evaluate factors associated with 28-day survival.

Results: A total of 142 patients treated with CZA alone (n=82) or in combination therapy (n=60) were included. We found 28-day survival rate, microbiological cure, and clinical success rate were 78% (111/142), 86% (87/101), and 48% (63/132), respectively. In multivariate analysis, there were no significant differences in 28-day survival between monotherapy group and combination therapy group (P=0.424). A relative lower microbiological cure rate can be observed in lower respiratory tract infection from univariate analysis (P=0.07). In addition, significantly better survival was observed in patients with creatinine clearance rate (CCr) ≥50 mL/min than CCr <50 mL/min (P=0.005).

Conclusion: CZA is an effective and important treatment option for CRKP infection even when it is treated as monotherapy. In patients with impaired renal function, a potential impact of CZA dose adjustments on poor survival outcomes has been observed, indicating the need for further research to determine optimal renal dose adjustment strategies.