Altered clearance of theophylline in children with Down syndrome: A case series

Down syndrome (DS) is a common cause of mental retardation resulting from t risomy 21. Previous reports have described altered pharmacokinetics and pha rmacodynamics in patients with DS. The authors report six cases of infants (2-19 months) with DS who demonstrated altered theophylline pharmacokinetic s. Clearance was prolonged in most of these patients. No overt toxicity to theophylline was noted in any of the cases. The authors propose that patien ts with DS are at increased risk for altered theophylline pharmacokinetics. The etiology for altered pharmacokinetics of theophylline may be due to th e interface between normal developmental changes and pharmacogenetic differ ences associated with DS and/or the secondary disease states and concomitan t drug therapy. (C) 1999 the American College of Clinical Pharmacology.