Related Experiment Video
Updated: Jun 24, 2026
A Reference Broth Microdilution Method for Dalbavancin In Vitro Susceptibility Testing of Bacteria that Grow Aerobically
Published on: September 9, 2015
Current recommended dosing of vancomycin for children with invasive methicillin-resistant Staphylococcus aureus
Adam Frymoyer1, Adam L Hersh, Leslie Z Benet
1Department of Medicine, University of California, San Francisco, CA 94143-0912, USA. frymoyera@peds.ucf.edu
Background:
Vancomycin area-under-the-concentration-time-curve (AUC) for 24 hours divided by the minimum inhibitory concentration (MIC) (AUC24/MIC) >400 optimally treats invasive methicillin-resistant Staphylococcus aureus (MRSA) infections in adults. It is unknown whether recommended vancomycin dosing regimens for children achieve this value.
Methods:
AUC24/MIC was calculated in children using vancomycin doses of 40 and 60 mg/kg/d. AUC24 was calculated as daily dose/vancomycin clearance. Vancomycin clearance in children was estimated by 2 approaches: (1) previously literature-reported vancomycin clearance, and (2) calculated vancomycin clearance using previously derived predictor models and a hypothetical population of healthy children. Representative MIC of hospital MRSA isolates was used (0.5, 1.0, and 2.0 microg/mL).
Results:
The MIC50/90 for pediatric MRSA isolates in the previous year was 1.0 microg/mL. With a dose of 40 mg/kg/d, both approaches consistently predicted AUC24/MIC <400 when MIC was 1.0 microg/mL. At 60 mg/kg/d, AUC24/MIC >400 was more readily achieved when MIC was 1.0 microg/mL, however, an MIC of 2.0 microg/mL resulted in AUC24/MIC <400 for both dosing regimens.
Conclusions:
A vancomycin dose of 40 mg/kg/d in children is unlikely to achieve the recommended pharmacodynamic target of AUC24/MIC >400 for invasive MRSA infections even when MIC is 1.0 microg/mL. A starting dose of 60 mg/kg/d should be used in settings where isolates with MIC of 1.0 are common. Alternatives to vancomycin should strongly be considered for patients with MIC > or =2.0 microg/mL.
Insights
Pediatric vancomycin dosing of 40 mg/kg/d is insufficient for invasive MRSA infections. A 60 mg/kg/d dose is recommended when MRSA MIC is 1.0, with alternatives needed for higher MICs.
Area of Science:
- Pharmacology
- Infectious Diseases
- Pediatrics
Background:
- Optimal treatment for invasive MRSA infections in adults requires a vancomycin area-under-the-concentration-time-curve (AUC24/MIC) >400.
- Current vancomycin dosing regimens in children have not been evaluated against this target.
Purpose of the Study:
- To determine if standard vancomycin doses (40 and 60 mg/kg/d) achieve the target AUC24/MIC >400 in children with invasive MRSA infections.
Main Methods:
- AUC24/MIC was calculated in children using 40 and 60 mg/kg/d vancomycin doses.
- Vancomycin clearance was estimated using literature values and predictive models.
- Calculations were performed using representative MRSA minimum inhibitory concentrations (MICs) of 0.5, 1.0, and 2.0 µg/mL.
Main Results:
- A vancomycin dose of 40 mg/kg/d consistently resulted in AUC24/MIC <400 when MRSA MIC was 1.0 µg/mL.
- A dose of 60 mg/kg/d more readily achieved AUC24/MIC >400 for MIC = 1.0 µg/mL.
- However, an MIC of 2.0 µg/mL led to AUC24/MIC <400 for both dosing regimens.
Conclusions:
- A 40 mg/kg/d vancomycin dose is unlikely to achieve the therapeutic target for invasive MRSA in children, even with MIC = 1.0 µg/mL.
- A starting dose of 60 mg/kg/d is recommended when MRSA isolates with MIC = 1.0 µg/mL are prevalent.
- Vancomycin alternatives should be considered for infections with MIC ≥ 2.0 µg/mL.
Related Concept Videos
01:26Pharmacokinetics in Pediatric Patients: Drug Excretion
01:29Drug Dosing: Infants and Children
01:20Estimation of k and VD of Aminoglycosides
01:25Clinical Significance of Antibiotic Resistance
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
01:19Dosage Interval and Administration Route: Determination Methods