Efficacy of linezolid-based salvage therapy compared with glycopeptide-based therapy in patients with persistent methicillin-resistant Staphylococcus aureus bacteremia

SummaryObjectiveWe evaluated the efficacy of linezolid-based salvage therapy compared with glycopeptide-based therapy in patients with persistent (≥7 days) methicillin-resistant Staphylococcus aureus bacteremia (MRSA-B).MethodsAll patients with MRSA-B during 2-year period at a tertiary-care hospital were prospectively enrolled. Linezolid-based salvage therapy was classified if patients switched glycopeptides to linezolid with/without carbapenem due to persistent MRSA-B. Covariate adjustment using the propensity score and inverse probability of treatment weighting (IPTW) using the propensity score were performed to control for bias in treatment assignment.ResultsOf 377 patients with MRSA-B, 90 with persistent MRSA-B were included. Of these, 38 (42%) were classified as linezolid-based salvage group and the remaining 52 (58%) as glycopeptide-based therapy group. The duration of persistent bacteremia (median 16 days vs. 10 days; P = 0.008) was longer in linezolid-based salvage group than in the comparator. However, the 30-day mortality (11% vs. 25%; P = 0.08) had a trend toward being lower in linezolid-based salvage group than those in the comparator. Logistic regression models with covariate adjustment and IPTW using propensity scores also revealed that linezolid-based salvage showed a trend toward having better outcome than the comparator, although this did not reach any statistically significance (OR 0.31; 95% CI 0.03–2.95 and OR 0.19; 95% CI 0.01–3.39, respectively).ConclusionsWhile having worse prognostic factors compared with glycopeptide-based therapy, linezolid-based salvage therapy revealed a trend toward better outcomes than the comparator. Our data suggest that linezolid-based salvage therapy would be considered in patients with persistent MRSA-B despite the use of glycopeptides therapy.