Pharmacokinetics of Vancomycin in Oncology Egyptian Paediatrics: A Dosage Adjustment Trial
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.