Activity of serum concentrations of daptomycin vs. vancomycin against vancomycin-susceptible and resistant Enterococcus faecium in the presence of albumin physiological concentrations: an in vitro pharmacodynamic simulation

  • L. Alou
  • L. Aguilar
  • M. J. Giménez
  • M. Torrico
  • D. Sevillano
Brief Report

Killing curves with daptomycin (56 μg/ml, the Cmax after 4 mg/kg) in media containing albumin physiological concentrations showed bactericidal activity against Enterococcus faecium, but due to its high protein binding (91.7%), cidal activity was delayed when compared to that in media without albumin [1]. This study explores the activity over 24 h of simulated serum concentrations of daptomycin (after 6 mg/kg od regimen) vs. vancomycin (1,000 mg bid regimen) against two vancomycin-susceptible but tolerant and one resistant E. faecium in an in vitro pharmacodynamic device using media containing albumin physiological concentrations. A one-compartment dynamic model was used to expose bacteria to changing study drug concentrations [2] using Mueller Hinton broth supplemented with albumin (4 g/dl). In daptomycin simulations, media was calcium-adjusted by adding 100 μg/ml of Ca2+ [3]. Albumin concentrations were determined by the bromcresol green method, ionized calcium concentrations were...


Vancomycin Daptomycin Initial Inoculum Bromcresol Bromcresol Green 
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To N. González for her technical assistance and J. Prieto for his critical review of the manuscript.

This study was supported by an unrestricted grant from Novartis Farmacéutica S.A., Barcelona, Spain.


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • L. Alou
    • 1
  • L. Aguilar
    • 1
  • M. J. Giménez
    • 1
  • M. Torrico
    • 1
  • D. Sevillano
    • 1
  1. 1.Microbiology Department, School of MedicineUniversity ComplutenseMadridSpain

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