Objectives: The incidence of infections caused by multidrug-resistant Pseudomonas aeruginosa (MDR-Pa) has become a concern of increasing relevance nowadays. Ceftolozane/tazobactam (C/T) is a novel fifth-generation cephalosporin/β-lactamase inhibitor combination with activity against MDR-Pa.
Methods: The clinical records of all patients diagnosed from May 2016 to May 2017 with an infection due to a MDR-Pa treated with C/T were retrospectively reviewed.
Results: A total of 23 patients with 24 episodes of infection due to MDR-Pa were included. The minimum inhibitory concentration (MIC) of C/T against MDR-Pa ranged from 0.75-8μg/mL. In 14 cases (58%) the use of C/T was off-label, including 8 respiratory tract infections (RTIs) and 6 skin and soft-tissue infections, whilst in 10 cases the use was for approved indications, including 7 urinary tract infections and 3 intra-abdominal infections. C/T was the first-line therapy in only three cases with a mean±standard deviation treatment duration of 9.3±4 days, and it was associated with another active drug (aminoglycoside or colistin) in 16 cases. The global clinical cure rate was 88% (21/24 episodes), and the 6-week mortality rate was 22% (5/23 patients) being higher in RTIs (37%). In these infections, three patients received 2/1g every 8h (q8h) and were cured without mortality, whilst three (60%) of five patients receiving 1/0.5g q8h died.
Conclusion: C/T had good clinical responses in different types of infection, including both FDA-accepted and off-label indications. The results support the use of higher doses in RTIs.
Keywords: Ceftolozane/tazobactam; Clinical experience; Multidrug-resistant organisms; Pseudomonas aeruginosa.
Copyright © 2018 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.