Ceftolozane/tazobactam for the treatment of Pseudomonas aeruginosa infections: A multicenter case series analysis.

INTRODUCTION: Pseudomonas aeruginosa displays resistance to several available antibiotics. Infections caused by this pathogen are associated with a high mortality, morbidity, and considerable healthcare resource utilization and costs. This study was aimed at describing the use of ceftolozane/tazobactam (C/T) for the treatment of patients with P. aeruginosa infections.

METHODS: Case series analysis of hospitalized patients treated with C/T for P. aeruginosa infections in five public Portuguese hospitals. Patients presenting with infections caused by this pathogen and receiving C/T for at least 72h during hospitalization were eligible.

RESULTS: Sixty-four hospitalized patients with P. aeruginosa infections treated with C/T were evaluated between December 2016 and July 2019. Most patients were aged between 60 and 79 years (53.9%). Patients presented a total of 68 P. aeruginosa infections, with respiratory infections being the most common (28.1%, 18 out of 64). Most P. aeruginosa strains (85.9%, 55 out of 64) were extensively drug-resistant (XDR). C/T was mostly used as targeted therapy (98.4%, 63 out of 64 patients) and as monotherapy (72.7%, 47 out of 64 patients). Combination therapy was used in 47.4% (9 out of 19) of patients with bacteriemia. Most patients had successful microbiological (79.2%, 42 out of 53) and clinical (78.7%, 48 out of 61) outcomes. All-cause in-hospital mortality rate was 34.4%.

CONCLUSION: The present case series contributes to the body of evidence suggesting that C/T is an effective and safe option for treating P. aeruginosa infections, namely those caused by XDR strains, both when used as mono- or combination therapy.