Pharmacokinetics of drugs: newborn perspective

Abstract

Safe and effective drug administration are pivotal goals of neonatal pharmacokinetics. Integrated knowledge of evolving pharmacokinetic principles, physiological characteristics, and maturational differences in term and preterm neonates is essential for effective, safe, and predictable drug response. Instances like 'Grey baby syndrome' chloramphenicol toxicity due to impaired glucuronidation and encephalopathy after hexachlorophene bath (to treat impetigo) due to increased transdermal absorption and impaired clearance have raised questions about our understanding of the complex interplay of factors in neonatal drug pharmacokinetics. This underscores the significance of knowledge and understanding of pharmacokinetic principles and the need for a population-specific approach. One must consider the complex relationship between multiple factors and differences among preterm neonates and young infants in terms of drug disposition before prescribing medications to the neonatal population. Consequently, clinical pharmacokinetics in neonates is as dynamic and diverse as the population. This review describes these dynamic changes leading to variable therapeutic efficacy or inadvertent exposures that can occur through the neonatal period. Therapeutic drug monitoring must be utilized to individualize the dosing of drugs in this vulnerable population whenever feasible. The objective of the review is to elucidate the principles of neonatal pharmacokinetics and the contribution of development, maturation, neonatal physiologic and pathologic states that govern neonatal pharmacokinetics so that drugs can be used efficaciously.