Over the past 15 years, new laws and regulations in the United States and the European Union have expanded to require the inclusion of pediatric patients in clinical drug trials. Before these laws were enacted, the US Food and Drug Administration (FDA) allowed the effectiveness of a medication to be extrapolated from studies in adults, as long as the course of the disease and the effects of the drug were sufficiently similar in children and adults. The problem that wasn't sufficiently appreciated at the time was that drug safety in children cannot be extrapolated from adult data.[1. R. Steinbrook, “Testing medications in children,” New Engl J Med, 347:1462-70, 2002.] There are critical differences in how a drug is processed–the drug's pharmacokinetics–in a child's body compared ...
