Subject
PedPal Lit; a drug - a truly age-dependent difference in pharmacodynamics. This may be true of both the desired action and adverse events. Examples are given. Programming by drugs is also a phenomenon almost exclusive to early life; Adult Aging/metabolism Bayes Theorem Child Clinical Trials/methods Humans PharmacogeneticsPharmacokinetics Research Design%X Children are not small adults. However; and response to; different 'host' response and different adverse drug reactions can all explain why some drugs behave differently in children. However; different disease variants; different pharmacodynamics; example s are discussed. Different pathophysiology; i.e. permanent effects result from a stimulus applied at a sensitive point in development ('critical window'); often in fetal or neonatal life. Again; stage of development can alter the action of; the main thesis of this review will be that children's responses to drugs have much in common with the responses in adults and indeed in other mammals. Often; we need to explore ways to avoid re-inventing the wheel by determining how data from adult animal and human models can help inform research and practice for children.