651. Ceftazidime/avibactam utilization in the national Veterans Affairs (VA) Healthcare System

Abstract Background Multidrug-resistant infections are challenging to treat, due underlying patient conditions, pathogen characteristics, and high resistance rates antibiotic treatments. Ceftazidime/avibactam (CAZ-AVI, approved in 2015) is treat complicated intra-abdominal infections, urinary tract hospital-acquired bacterial pneumonia, ventilator-associated pneumonia. As newer therapies come market, limited data exist about their use real-world practice. Therefore, we sought describe the utilization of CAZ-AVI clinical Methods This national retrospective cohort study included hospitalized VA patients receiving from 2015 through 2021. Cultures, infection diagnoses, demographics, comorbidities, treatments, outcomes were assessed this cohort. Results During period, 1,048 unique received CAZ-AVI, with a mean age 71.5 (±11.9) years. The was predominantly male (98.3%) White (66.2%, Black 27.7%). most common organism-culture site combinations Klebsiella-urine (19.6%), Pseudomonas aeruginosa-respiratory (14.0%), aeruginosa-urine (10.1%), Escherichia coli-urine (6.9%) Klebsiella-blood (6.9%). median time initiation admission 6 days, subsequent 14-day hospital stay. Median length therapy 8 days. Most changed 3 times before starting CAZ-AVI. Treatment heterogeneity both prior (89.6%) during treatment (85.6%). concomitant vancomycin (41.4%), meropenem (24.1%), cefepime (15.2%), piperacillin/tazobactam (15.2%). Inpatient mortality 23.6%, one-third had hospitalization (35.1% 2021). Conclusion Utilization increased 2018 has since stabilized Healthcare System. been utilized complex, difficult-to-treat substantial variation causative site. Disclosures Aisling R. Caffrey, PhD, M.S., AbbVie Inc.: Grant/Research Support|Gilead Sciences Support|Merck & Co., Inc: Advisor/Consultant|Merck Support|Shionogi Support Haley J. Appaneal, PharmD, Ph.D., Shionogi Kerry L. LaPlante, Pharm.D., FCCP, FIDSA, FIDP, Sciences, Support|Melinta Therapeutics, Inc.,: Support|Nabriva Therapeutics US, Support|Ocean Spray Cranberries, Support|Pfizer Pharmaceuticals: Support|Shionogi, Support|Tetraphase Pharmaceuticals.: Support.