Pharmacokinetic analysis of vancomycin in steady state in pediatric cancer patients.

ABSTRACT

Thirty children suffering from different types of malignancies, neutropenic fever, and suspected staphylococcal bacteremia were evaluated for the pharmacokinetics of vancomycin in steady-state conditions and compared with eight children suffering from proven methicillin-resistant staphylococcal infection. All the studied population received intravenous vancomycin at 40 mg/kg daily divided into four daily doses. The individual pharmacokinetic parameters were calculated using a one-compartment model for two blood vancomycin samples. The mean (+/- SD) half-time (t1/2, hours), clearance (L/h/kg), Vss (L/kg), Cmax (microgram/mL), and Cmin (microgram/mL) were 10.5 (7.9) and 14.9 (9.1) hours; 0.11 (0.14) and 0.06 (0.06) L/h/kg; 0.62 (0.33) and 1.3 (0.6) L/kg; 28.3 (11.8) and 22.3 (9.8) micrograms/mL; and 5.7 (6.0) and 7.4 (4.8) micrograms/mL for the malignancy and control groups, respectively. The malignancy group had a significantly shorter t1/2 (P = .005), higher clearance (P = .005), and lower Cmin (P = .03) in comparison with the control group. It is suggested that the prescription of vancomycin at 40 mg/kg daily, divided into four daily doses, is safe and will provide a peak blood level of vancomycin sufficient to cover the broad spectrum of staphylococcal bacteria. The vancomycin dose should be individualized, based on an individual pharmacokinetic profile.