RESUMO
The purpose of this study is to determine the pharmacokinetic parameters of vancomycin in Egyptian paediatric oncology patients and to evaluate the factors that influence the variability of the pharmacokinetic parameters in this population. Vancomycin serum concentration at steady state was determined in 51 paediatric cancer patients who were treated with vancomycin multiple intravenous infusions. Also individual vancomycin pharmacokinetic parameters were calculated assuming one compartment model. The mean vancomycin total body clearance and mean vancomycin volume of distribution were significantly higher among the age range of 2 to <12 years as compared with older age. Obese patients showed significant lower values of peak and trough vancomycin concentrations than those of normal and underweight patients. A significant correlation was found between the estimated creatinine clearance (Schwartz formula) and vancomycin total body clearance in the studied patients. Also, a significant direct correlation between vancomycin volume of distribution and ratio between blood urea nitrogen (mg/dl)/weight (kg) was found. As a conclusion, age and obesity were identified as the most important factors influencing vancomycin total body clearance, volume of distribution and serum concentrations in the studied patients.
