1050. Oral Antibiotics for the Treatment of Gram-Negative Bloodstream Infections: Prescribing Practices and Outcomes at a Large Academic Medical Center

BACKGROUND: There is limited data to guide the use of oral (PO) antibiotics for the treatment of Gram-negative (GN) bloodstream infection (BSI). The objective of this study was to describe the characteristics and outcomes at a large academic medical center. METHODS: Retrospective observational cohort of adult patients (age ≥18 years) with at least one blood culture positive for aerobic Gram-negative organism(s) treated with antibiotic therapy (IV or oral [PO]) at University of Medical Center from November 2015 to May 2017. Oral antibiotics were described based on bioavailability. The primary outcome of interest was 30-day infection-related readmission. Secondary objectives included evaluation of patient characteristics associated with PO antibiotic use. RESULTS: During the defined study period 310 patients met inclusion; 113 (36.5%) were switched to PO antibiotic therapy for the treatment of GN BSI within a median of 5 (IQR 3–11) days. Oral antibiotics were initiated at discharge for 50 (44%) of patients switched. Patients switched to PO were less likely to have has a stay in the ICU (24.8% vs. 47.7%, P < 0.0001) and were less likely to have an ID consult (57.5% vs. 71.1%, P = 0.034). There was no difference in median Charlson Comorbidity Score (2, IQR 0–4). The most common sources of infection among those switched to PO agents were urinary (50, 44.2%) and intra-abdominal (25, 22.1%). The majority of patients were placed on a PO agent with high bioavailability (61, 54%), which included levofloxacin and moxifloxacin. There was a slightly higher proportion of use of high (vs. low) bioavailable antibiotics in patients with ID consult compared with those without (59% vs. 41%, P = 0.053). PO antibiotics were more frequently prescribed for patients discharged home (78, 69%) compared with patients discharged to Rehab/Short-term facility (28, 24.8%). Thirty-day hospital readmission was more common among the patients treated with PO antibiotics (18.6 vs. 8.1%, P = 0.006); however, ID-related readmission was rare (0.9% vs. 1%, P = 0.91). CONCLUSION: Urinary and intra-abdominal sources and home discharge were common among those with PO antibiotic use. ID-related outcomes were similar among those treated with IV vs. PO agents. More research is necessary to determine optimal time to PO antibiotic switch. DISCLOSURES: K. Claeys, Nabriva: Scientific Advisor, Consulting fee. Melinta: Scientific Advisor, Consulting fee. E. Heil, ALK-Abelló: Grant Investigator, Research grant.