(633) Impact of Linezolid Versus Vancomycin as Preferred Gram-Positive Agent in the Emergency Department

Introduction: Linezolid (LZD) and vancomycin are utilized for empiric treatment of suspected gram-positive infections with need for intravenous (IV) methicillin-resistant Staphylococcus aureus (MRSA) coverage. Literature demonstrates clinical equivalence for many indications but lacks analysis of practical differences that may lead to a preferred agent. LZD has a pre-mixed IV formulation that does not need compounding, weight or renal dose adjustment, and may offer a cost advantage over vancomycin. The purpose of this study was to evaluate the impact of an education initiative encouraging empiric use of LZD over vancomycin on time to first antibiotic dose and utilization patterns in the Emergency Department (ED).

Methods: Baseline data was collected for doses of IV LZD and vancomycin for July-December 2023 in the ED of a large community teaching hospital. An educational presentation was performed in January 2024 to pharmacists and relevant physician groups reviewing potential advantages of LZD and baseline trends. Follow-up data was collected for January-April 2024. Descriptive statistics were calculated for outcomes. The primary outcome was time from order verification to first dose administration in the ED. Secondary outcomes were percent of total ED doses dispensed for each agent, impact on hospital anti-MRSA duration of therapy (DOT) and purchasing costs of LZD and vancomycin.

Results: Data was reviewed for 2,331 administrations of LZD/vancomycin in July-December 2023 and 1,899 administrations in January-April 2024. Median time (minutes) from order entry to first dose was 18 minutes faster with LZD than vancomycin (41 vs 59, p< 0.001) in the pre-intervention period. After the education initiative, a significantly faster administration time was maintained, with LZD 23 minutes faster than vancomycin (41 vs 64, p< 0.001). Percent of total doses as LZD increased from a mean of 36% to 72% in the post-intervention period. Total monthly mean drug purchasing spend and anti-MRSA DOT/1000 patient days were similar between groups.

Conclusions: Empiric utilization of LZD demonstrated shorter time to first dose compared to vancomycin and an education initiative increased utilization of empiric LZD in the ED. Costs and anti-MRSA DOT were similar. Future research should investigate impact on other clinical outcomes.