A multicenter US study found that the combination antibiotic ceftolozane/tazobactam was successfully used to treat a variety of complicated, multidrug-resistant infections in outpatient settings, researchers reported yesterday in Open Forum Infectious Diseases.
Ceftolozane/tazobactam (C/T) was the first cephalosporin/beta-lactamase inhibitor combination approved by the US Food and Drug Administration and has generally been used to treat adults with complicated infections—such as intra-abdominal infection (IAI), urinary tract infection (UTI), and hospital-acquired/ventilator-associated pneumonia (HABP/VABP)—in acute care settings. Little real-world data on outpatient use is available. To evaluate use of the drug as outpatient parenteral antimicrobial therapy (OPAT), researchers evaluated outcomes among patients treated at 33 office infusion centers from 2015 through 2020.
Among the 126 patients identified (median age, 59; 59% male; 39% immunocompromised), bone and joint infection (BJI) was the most common infection (27%), followed by UTI (23%), respiratory tract infection (RTI, 18%), IAI (16%), complicated skin and soft tissue infection (cSSTI, 13%), and bacteremia (3%). Pseudomonas aeruginosa (63%) was the most common gram-negative pathogen identified, followed by Escherichia coli (13%) and Klebsiella spp (7%). Of the P aeruginosa isolates, 66% were multidrug-resistant and 45% were carbapenem-resistant. Extended-spectrum beta-lactamase producers were identified in 44% of all Enterobacterales isolates.
Overall clinical success was achieved in 84.7% of patients, with successful outcomes observed in 72.7% of BJI patients, 96.6% of UTI patients, 95.4% of RTI patients, 80% of IAI patients, 82.4% of cSSTI patients, and 66.7% of bacteremia patients. Non-successful outcomes were due to persistent infections (9.7%) and drug discontinuations (5.6%).
"We believe these real-world findings support the use of C/T in the outpatient setting for serious Gram-negative infections," the study authors concluded.