Facilitating pharmacokinetic studies in children: a new use of dried blood spots.

Pharmacokinetic data are used to develop dosing regimens for medicines. The dose regimens of many drugs administered to children have historically been based on pharmacokinetic data generated in adults. The 'adult' dose was simply adjusted to the child's body weight or surface area. This practice is potentially unsafe and not acceptable to drug regulatory agencies. Obtaining pharmacokinetic data in children is beset with ethical issues and technical challenges as pharmacokinetic studies require repeated measurement of drug levels in blood. Dried blood spot (DBS) samples used in conjunction with population pharmacokinetic modelling techniques is one potential method for performing pharmacokinetic studies in children. In this article, we review the DBS technique for performing pharmacokinetic studies and highlight issues that still need to be addressed to establish DBS as a method for performing pharmacokinetic studies in children.