Modelling approaches to dose estimation in children.

Most of the drugs on the market are originally developed for adults and dosage selection is based on an optimal balance between clinical efficacy and safety. The aphorism 'children are not small adults' not only holds true for the selection of suitable drugs and dosages for use in children but also their susceptibility to adverse drug reactions. Since children may not be subject to dose escalation studies similar to those carried out in the adult population, some initial estimation of dose in paediatrics should be obtained via extrapolation approaches. However, following such an exercise, well-conducted PK-PD or PK studies will still be needed to determine the most appropriate doses for neonates, infants, children and adolescents.