1977. Comparative Effectiveness of Linezolid vs. Trimethoprim–Sulfamethoxazole for Acute Bacterial Skin and Skin Structure Infections (ABSSSIs) at a Veterans Affairs Hospital

BACKGROUND: Linezolid (LZD) and trimethoprim–sulfamethoxazole (TMP-SMX) are both used in the treatment of acute bacterial skin and skin structure infection (ABSSSI) with differing adverse event profiles to guide usage, but their comparative efficacies in severe ABSSSI remain unclear. METHODS: This retrospective cohort study evaluated patients admitted to the VA St. Louis Health Care System for treatment of an ABSSSI between April 18, 2000 and October 16, 2017 and discharged with a prescription for ≥5 days of LZD or TMP-SMX. The primary outcome was clinical failure, defined as a composite of an Emergency Department visit, clinic visit, inpatient admission, extension of antibiotics, change of antibiotic regimen for any reason, or the presence of an adverse reaction occurring in the 14 days after completion of the outpatient regimen. Adverse reactions evaluated were acute kidney injury, hyperkalemia, neutropenia, thrombocytopenia, and anemia. The secondary outcome evaluated risk factors for clinical failure with multivariate logistic regression analysis. Potential factors to be included in the analysis were drug choice, duration of intravenous antibiotic use while inpatient (<24 hours, ≥24 hours to ≤48 hours, >48 hours), identification of methicillin-resistant Staphylococcus aureus (MRSA) in culture, MRSA nasal colonization, and incision and drainage. RESULTS: A total of 139 patients were included in the analysis; 51 treated with LZD and 88 treated with TMP-SMX. Length of hospital stay was greater in the LZD group (6.05 days vs. 3.69 days [P = 0.023]), as was antibiotic use during hospitalization (98% [49/50] vs. 86% [77/90]; P = 0.019). The mean day supply of antibiotic dispensed at discharge was 10.18 in the LZD group and 9.64 in the TMP-SMX group (P = 0.48). Twenty-two percent (11/51) of patients treated with LZD and 18% (16/88) of those treated with TMP-SMX (P = 0.878) experienced clinical failure. Only receipt of antibiotics for 24–48 hours during hospitalization met criteria for inclusion in the multivariate analysis, but was not significantly associated with clinical failure (0.367 [95% CI 0.083–1.63]; P = 0.187). CONCLUSION: There was no difference in the rate of clinical failure between patients treated with LZD or TMP-SMX for severe ABSSSI. DISCLOSURES: All authors: No reported disclosures.