Efficacy of ceftazidime/avibactam versus other antimicrobial agents for treating multidrug- resistant Pseudomonas aeruginosa: a propensity-matched retrospective analysis

Introduction Multidrug-resistant Pseudomonas aeruginosa (MDRPA) is a life-threatening infection with limited treatment options. As a novel combination drug of cephalosporin and beta-lactamase inhibitor, ceftazidime/avibactam (CAZ/AVI) is not much used in clinical treatment of MDRPA infections. To fill in this knowledge gap, a single-center real-world study was conducted. Methods This single-center retrospective observational study included MDRPA-infected patients treated with CAZ/AVI or other antimicrobial agents between January 2019 and April 2021. Propensity score-matched and binary logistic regression analysis was used to compare the clinical and microbiological efficacy between CAZ/AVI and other antimicrobial agents. Results Totally 363 patients with MDRPA infection were enrolled, including 49 patients treated with CAZ/AVI and 314 patients treated with other antimicrobial agents. The CAZ/AVI group exhibited a reduced failure rate of clinical treatment (P = 0.012, OR = 0.381, 95% CI 0.180 - 0.807). Subgroup analysis showed single lung infection was a significant risk factor for clinical treatment failure in patients treated with other antimicrobial agents (P = 0.023, OR = 2.568, 95% CI 1.138 - 5.796). No significant discrepancy was observed in microbiological efficacy between the two groups (P = 0.159, OR = 0.587, 95% CI 0.280 - 1.232), or in clinical and microbiological efficacy between CAZ/AVI monotherapy and combination therapy. Conclusions CAZ/AVI demonstrates superior clinical efficacy against MDRPA in comparison to other antimicrobial agents. However, the administration of CAZ/AVI as part of combination therapy does not provide any clear benefits over monotherapy. Patients with single pulmonary infection caused by MDRPA show better clinical efficacy with CAZ/AVI. Further larger studies are needed to substantiate our findings.