Low Serum Trough Concentrations and High Vancomycin Minimum Inhibitory Concentration in Methicillin-Sensitive Staphylococcus aureus From Hemodialysis Patients in Brazil

Abstract

Background: The empiric antimicrobial therapy for bacteremia of long-term hemodialysis (HD) outpatients is currently based on the combination of vancomycin and gentamicin because of the high frequency of isolated Staphylococcus species. The vancomycin trough level range from 15 to 20 mcg/mL is expected for therapeutic success against methicillin-resistant Staphylococcus aureus with vancomycin minimum inhibitory concentration (MIC) ≥1.0 mcg/mL. Despite the availability of clinical practice guidelines for vancomycin therapeutic drug monitoring, these target serum concentrations are not reached in many patients. Methods: In this study, the authors investigated the vancomycin trough levels in 20 HD patients with S. aureus bacteremia and the antimicrobial susceptibility pattern of 45 S. aureus strains isolated from 45 HD patients. The vancomycin serum concentration was determined by chemiluminescent assay. The MIC was determined by broth microdilution method. Results: None of the HD patients included in this study had vancomycin trough concentrations within the therapeutic range. Also, the vancomycin MIC for most methicillin-sensitive S. aureus isolated from bacteremia was ≥1.0 mcg/mL. Conclusions: The therapeutic range of vancomycin was not achieved, and vancomycin MIC was surprisingly high in methicillin-sensitive S. aureus.

Comparison of Vancomycin Clearance Between Augmented Renal Clearance and Normal Renal Function in Critically Ill Infants: A Population Pharmacokinetics Study

“…In the past, we used the vancomycin trough concentration (C min ) as a therapeutic target to optimize the vancomycin dosage regimen. However, some studies have reported that the C min was not associated with the success of infection treatment 13–15 . The Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines recommend the area under the serum concentration time curve over 24 h/minimum inhibitory concentration ratio (AUC 0–24 /MIC) >400 as the ideal pharmacodynamic index to guide vancomycin dose adjustment 16 …”

“…However, some studies have reported that the C min was not associated with the success of infection treatment. [13][14][15] The Infectious Diseases Society of America (IDSA) Clinical Practice Guidelines recommend the area under the serum concentration time curve over 24 h/minimum inhibitory concentration ratio (AUC 0-24 /MIC) >400 as the ideal pharmacodynamic index to guide vancomycin dose adjustment. 16 Therefore, the purpose of this study was to compare the vancomycin CL in critically ill infants with augmented renal clearance and with normal renal function, and to optimize the dosage regimen for infants with augmented renal clearance using AUC 0-24 /MIC.…”