An assessment of vancomycin pharmacokinetic variability in pediatric cardiology patients

Abstract

Objectives: To establish the steady-state pharmacokinetic profile of vancomycin in pediatric cardiology patients; determine an empiric vancomycin dose; and evaluate the correlation between fluid balance and volume of distribution (Vd), serum creatinine and clearance (CL), and daily dose of furosemide and Vd.

Methods: Retrospective pharmacokinetic evaluation in 36 pediatric cardiology, cardiac surgery, or cardiac transplant patients treated with vancomycin. The pharmacokinetic profile for vancomycin including elimination half-life (t1/2), elimination rate constant (ke), volume of distribution (Vd), and clearance (CL) was calculated for each patient. The relationship between fluid balance and Vd, serum creatinine and CL, and the total daily dose of furosemide and Vd was evaluated.

Results: The patient population had an average half-life of 5.9±1.2 hr and a Vd of 0.4±0.12 L/kg. A statistically significant correlation was noted between serum creatinine and CL (r(2)=0.19, P<0.01). Additionally, a statistically significant correlation exists between the total daily furosemide dose and the Vd (r(2)=0.31, P<0.01). A dose of 10 mg/kg/dose every 12 hrs was predicted to result in the greatest number of serum vancomycin concentrations within the reference range.

Conclusions: Routine monitoring of serum vancomycin concentrations is prudent for this population, and special consideration should be given to those with elevated serum creatinine and to those receiving large doses of furosemide.

Keywords: Vancomycin; cardiology; pediatrics; pharmacokinetics.