Early use of daptomycin versus vancomycin for methicillin-resistant Staphylococcus aureus bacteremia with vancomycin MIC>1 mg/L: a matched cohort study.
Clin Infect Dis. 2013 Feb 28;
Authors: Murray KP, Zhao J, Davis SL, Kullar R, Kaye K, Lephart P, Rybak MJ
Abstract
Background.?Recent reports have described decreased effectiveness with vancomycin treatment for methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) when the vancomycin minimum inhibitory concentration (MIC) is >1 µg/mL. Methods.?This matched, retrospective cohort study compared the clinical effectiveness of daptomycin with that of vancomycin for the treatment of MRSAB with vancomycin MICs >1 µg/mL. The primary outcome was clinical failure, defined as a composite of 30 day mortality or bacteremia persisting for ?7 days. Results.?One-hundred seventy patients were matched 1:1 with respect to the antimicrobial. In the daptomycin group, all patients received <72 hours of vancomycin (median, 1.7 days [interquartile range, 1.1-2.3 days]) prior to switching to daptomycin. The rate of clinical failure at 30 days was significantly lower in the daptomycin arm compared to the vancomycin arm (20.0% vs 48.2%; P<0.001). Both 30-day mortality and persistent bacteremia were significantly lower in the daptomycin group compared to the vancomycin group ([3.5% vs 12.9%; P=0.047] and [18.8% vs 42.4%; P=0.001], respectively). Logistic regression confirmed the association between vancomycin treatment and increased risk of clinical failure (adjusted odds ratio, 4.5; 95% confidence interval, 2.1-9.8). Conclusions.?This is the first matched study comparing early daptomycin versus vancomycin for the treatment of MRSAB when the vancomycin MIC is >1 µg/mL. Treatment with daptomycin resulted in significantly improved outcomes, including decreased 30 day mortality and persistent bacteremia. These results support the practice of switching early from vancomycin to daptomycin for the treatment of MRSAB when the vancomycin MIC is >1 µg/mL.
PMID: 23449272 [PubMed - as supplied by publisher]