Real-world Analysis of Prescribing Patterns and Susceptibility of Ceftolozane/Tazobactam (C/T) Treatment using an Electronic Medical Record (EMR) Database in the United States

BACKGROUND: C/T is a novel antipseudomonal cephalosporin, combined with tazobactam, an established β-lactamase inhibitor. C /T is approved for treatment of complicated urinary tract (cUTI) and complicated intraabdominal infections c(IAI). The objective is to provide real-world data describing the prescribing patterns of C/T and antimicrobial susceptibility profiles of the isolates in these patients (pts). METHODS: Patients from the Predictive Health Intelligence Environment were included, if they were hospitalized and prescribed C/T for greater than 48 hours between 1/14/15-5/1/17. Classification of infection type was based on diagnosis codes. Empiric was treatment given prior to culture results. Escalation was the addition of another GN antibiotic for at least 48 hours after initial GN therapy. Pan-β-lactam resistance (PBL-R) were isolates resistant to cefepime, ceftazidime, piperacillin/tazobactam, meropenem, and imipenem. RESULTS: 394 patients had 524 C/T encounters. The majority of the patients were male 235 (60%) and Caucasian 221 (56%) with an average age of 56 ± 17 years. Fifty percent of patients received antimicrobials within 30 days prior to the index hospitalization. Common comorbidities were chronic pulmonary disease 175 (44%), renal disease 140 (36%) and diabetes 132 (34%), with an average Charlson Comorbidity Index of 3.8 ± 3. A majority 350 (89%) of patients received C/T within the first week of hospitalization. Patients receiving C/T most commonly had respiratory infections 189 (48%), cUTI 163 (41%) and cIAI 107 (27%). The most common (317/394; 80%) isolated pathogen was Pseudomonas aeruginosa (PSA).The median and interquartile range of C/T duration was 9 (4-18) days. C/T was empiric for 77 patients and in 71 (18%) of patients C/T was the only GN therapy received. 110 (28%) were escalated to C/T after other GN therapy, 197 (50%) had some overlapping GN coverage and 14 (3.5%) patients received escalation after receipt of C/T. Susceptibility to CT was demonstrated in (69/75; 92%) of PSA including (65/71; 92%) of PBL-R isolates. Fig 1. CONCLUSION: C/T demonstrated high in vitro susceptibility, including against PBL-R isolates. Most patients received C/T for treatment of PSA and only a few patients required escalation of therapy after C/T. DISCLOSURES: J. M. Pogue, Achaogen, Inc.: Consultant, Consulting fee. L. Puzniak, Merck: Employee, Salary. S. Merchant, 1Merck & Co., Inc.: Employee and Shareholder, Salary. E. Rhee, Merck: Employee, Salary