In order to provide safe and effective drug therapy to neonates, it is necessary to know about and understand the impact their development has on the pharmacokinetics and pharmacodynamics of drugs. The fact that children are different and neonates very different from adults means that, in neonates, it would be unwise to dose medications by scaling down adult doses proportionately, simply attempting to match their smaller weight and/or body surface area. When one makes decisions about neonatal drug therapy, one must not only take into consideration the available data but also critically assess and interpret this information within the context of fetal development and maturational processes as well as within the context of diseases that might affect a drug’s biodisposition. This book includes the latest information on the regulation and scientific basis of drug development and also provides a rationale for formula development for preterm infants. It offers guidance on how to translate pharmacokinetic data into dosing recommendations and also covers legal and regulatory issues relating to neonatal pharmacotherapy.