We present our experience in patients with hematologic malignancy and Pseudomonas aeruginosa infection treated with ceftolozane-tazobactam. We performed a single-center case-control study comparing patients with hematologic malignancy and P. aeruginosa infection treated with ceftolozane-tazobactam (study group) with similar patients not treated with ceftolozane-tazobactam (control group) to assess safety and efficacy. Nineteen cases and 38 controls were analyzed. Cases were younger (45.6 years versus 57.6 years; P = 0.012) and less frequently had bacteremia (52.6% versus 86.8%; P = 0.008). They also had worse Multinational Association for Supportive Care in Cancer (MASCC) scores (10.2 versus 16.1; P = 0.0001), more hospital-acquired infections (78.9% versus 47.4%; P = 0.013), and more extremely drug-resistant (XDR) P. aeruginosa infections (47.4% versus 21.1%; P = 0.015). Cases received a median of 14 days (7 to 18 days) of ceftolozane-tazobactam (monotherapy in 11 cases [57.9.6%]). Ceftolozane-tazobactam was mostly used as targeted therapy (16 cases; 84.2%) because of resistance (9 cases; 47.4%), failure (4 cases; 21.1%), and toxicity (3 cases; 15.8%). Ten cases had bacteremia (52.6%). The sources were pneumonia (26.3%), catheter-related bacteremia (21.1%), primary bacteremia (21.1%), and perianal/genital (15.7%), urinary (10.5%), and skin/soft tissue (5.3%) infection. No toxicity was attributed to ceftolozane-tazobactam. More than 60% had neutropenia, and 15.8% fulfilled the criteria for sepsis. There were no significant differences in clinical cure at day 14 (89.5% versus 71.1%; P = 0.183) or recurrence (15.8% versus 10.5%; P = 0.675). Thirty-day mortality was lower among cases (5.3% versus 28.9%; P = 0.045). Ceftolozane-tazobactam was well tolerated and at least as effective as other alternatives for P. aeruginosa infection in patients with hematologic malignancy, including neutropenic patients with sepsis caused by XDR strains.

This type of program could help adjust antibiotic treatment when inappropriate, reducing antibiotic use and costs, length of stay, CDI and related mortality.