Antibiotic therapy for severe infections in infants and children

Abstract

Guidelines for the use of antibiotics in infants and children must take into account drug absorption, distribution, metabolism, and excretion. In the developing human being, these factors may differ significantly from those in the adult, and so there are differences in therapeutic efficacy and toxicity. Certain drugs should be avoided in the neonate because of known toxicity; these include the sulfonamides, tetracycline, and high doses of chloramphenicol. Antibiotic therapy should be modified in neonates in several ways because of the biologic immaturity of systems important for the termination of drug action, such as the liver and kidney. Because of poor conjugation, inactivation, or excretion, the administration of many antibiotics results in higher and more prolonged serum levels than those produced in older infants. Thus, in the neonate, the dosages of many antibiotics have to be lower and intervals between administration longer. In the case of gentamicin, studies in the 6-month to adult age group have shown that children less than 5 years old require almost twice as much of the drug as do children older than 10 years or adults to achieve similar peak concentrations. The appearance throughout the United States of strains of Haemophilus influenzae, type b, that are resistant to ampicillin has necessitated a change in the initial antibiotic therapy given to children with bacterial meningitis. There are few uses for tetracycline in pediatric practice.