Clinical pharmacokinetic trials in pediatric patients based on a peak-and-trough sampling design

The area under the concentration. time curve(AUC) and/or oral clearance(CL/F) of drugs is a key pharmacokinetic parameter to evaluate drug exposure in patients. In the present study, we conducted a clinical trial to evaluate the pharmacokinetics of bosentan in Japanese pediatric patients. Plasma samples were taken twice at two time points corresponding to the peak concentration(C_) and trough concentration(C_) following repetitive oral drug administration to the petients. A large interindividual variability was observed in plasma concentrations of bosentan, and the weight-normalized values of CL/F were correlated negatively with age. We confirmed that the peak-and-trough sampling design is promising for the clinical repeated-dose pharmacokinetic trial for drugs.