THEOPHYLLINE PHARMACOKINETICS IN THE YOUNG INFANT

Abstract

Theophylline is a drug widely used in the treatment of asthmatic children. The pharmacokinetics of theophylline were investigated in 13 infants, 4-18 mo. of age. An inverse relationship was found between theophylline half-life and age. Volume of distribution did not differ from that reported by other authors in similarly aged infants. Childhood clearance rates of elimination can be achieved by 6 mo. of age. The decreased theophylline elimination observed in the smaller infant indicates that the usual pediatric dosing recommendations cannot be used routinely. Until more specific data are available in the infant under 6 mo., the authors reaffirm individualization of theophylline dosage to maintain therapeutic levels and avoid toxicity.