Neonatal pharmacology

The absorption, distribution, metabolism and excretion of drugs in a neonate differ markedly from those of older children. The neonate undergoes rapid developmental change from birth, which alters the pharmacokinetic profile of many drugs. The pathology seen in neonates can also have marked effects on drug handling; low cardiac output states, raised intra-abdominal pressure, hepatic and renal disease have significant implications for drug pharmacokinetics. There is also considerable interpatient variability concerning all aspects of drug disposition. These factors make accurate drug administration difficult, and leave the newborn particularly susceptible to adverse drug reactions, morbidity and mortality. By applying neonatal pharmacokinetic principles to individual drugs, we identify important differences between neonates and older children. Adverse effects of commonly used drugs in neonates may be reduced by applying neonatal pharmacokinetic principles. Anaesthetic agents, sedatives, analgesics and local anaesthetics are discussed in this article in relation to their particular behaviour in neonates.