743. Evaluation of Adverse Drug Reactions due to Common β-Lactam Therapies Among Patients Enrolled in an Outpatient Parenteral Antimicrobial Therapy (OPAT) Program

BACKGROUND: The UNC Medical Center Outpatient Parenteral Antimicrobial Therapy (OPAT) program was started in 2015 to provide multidisciplinary monitoring and management of patients discharged on parenteral antimicrobials. Laboratory abnormalities and adverse drug reactions (ADRs) are potential complications of OPAT that may result in readmission and treatment changes. The purpose of this study was to evaluate the time to first ADR for OPAT patients treated with BL therapies for diabetic foot infections (DFI) and osteomyelitis (OM). METHODS: This was a retrospective cohort study of patients enrolled in the UNC OPAT program between January 2015 and September 2018 for treatment of DFI or OM. Included patients received one of the following BL: cefepime, ceftriaxone, ertapenem, meropenem, and piperacillin/tazobactam. The primary outcome was time to first ADR during OPAT. Secondary outcomes were estimation of risk of ADR during OPAT for each medication; and ADR types and frequencies observed among patients treated with BL alone or with concomitant vancomycin or daptomycin. RESULTS: In this cohort, 178 OPAT patients received 193 OPAT courses, for a median duration of 42 days (IQR 38–50). The average patient age was 55 years, and 68% were male. Ertapenem was the most commonly prescribed BL (76 courses, 39%), followed by ceftriaxone (29, 15%), cefepime, (41, 21%), piperacillin/tazobactam (30, 16%) and meropenem (17, 9%). Approximately 40% (76) patients received concomitant vancomycin. ADR was documented in 48 patients (27%) and 56 courses of therapy (29%). Kaplan–Meier-estimated risk of at least one ADR in the first 8 weeks of therapy was 38.7% (95% CI 29.1% to 48.2%). ADR resulted in 32 therapy changes and 8 readmissions. CONCLUSION: More than one-third of patients treated with BL for treatment of DFI and/or OM are at risk of ADR within 8 weeks. ADR commonly resulted in treatment changes, and possible hospital readmission. BL therapy is associated with significant ADR risk, and careful selection and monitoring is essential for optimal patient safety during OPAT. [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.