Developmental pharmacology: relationship to drug use

The pharmacodynamics of drugs in children have been poorly understood, and only recently have technological advances permitted the issue to be studied. Factors that affect drug use in infants include absorption, distribution, protein binding, metabolism, renal elimination, and volume of distribution. Selection of antibiotics in this patient population should reflect commonly isolated organisms, such as staphylococci, group B streptococci, Escherichia coli, and gram-negative bacteria. An antibiotic must also have good penetration into the central nervous system. Displacement of bilirubin from its albumin-binding sites by drugs or endogenous substrates can lead to kernicterus, or bilirubin encephalopathy. The free bilirubin, rather than total concentration, appears to be only partly responsible for the development of kernicterus.