ABSTRACT
Large inter-individual variability has been reported for vancomycin pharmacokinetics in pediatric patients. On the other hand, the pharmacokinetic parameters of vancomycin should be known in order to individualize its dosage regimen. Therefore, this study was designed and conducted to assess the steady-state vancomycin serum concentration and pharmacokinetics in a population of Iranian pediatric patients. Vancomycin serum concentration at steady-state was determined in 62 children who were treated with vancomycin intermittent intravenous infusion. Also individual steady-steady pharmacokinetic parameters [total body clearance, apparent volume of distribution and elimination half-life] were determined in 30 patients who had both peak and trough vancomycin levels assuming one-compartment model. Calculated pharmacokinetic parameters were compared among patients with different underlying diseases and also with the results of similar studies that used one-compartment pharmacokinetic model for description of serum concentration of vancomycin at steady-state. More than half of the measured vancomycin serum concentrations were outside the recommended therapeutic range. Median trough concentration was significantly lower in critically ill patients as compared to patients of other disease categories. Although critically care patients showed greater values of apparent volume of distribution and also vancomycin clearance, no statistically significant difference of the calculated pharmacokinetic parameters could be detected among different groups of patients. While calculated volume of distribution for patients of this study was greater than those of similar studies, this difference could not be considered statistically significant in the majority of disease categories. It may be concluded that design of vancomycin dosage regimens according to the recommended and general guidelines in literature [e.g. based on patient creatinine clearance] could not result in the desired therapeutic serum concentrations in the study population