title: Relationships between plasma theophylline clearance, liver volume and body weight in children and adults.
abstract: The influence of liver volume and body weight on plasma theophylline clearance was investigated in asthmatic children and adults. A linear relationship (r = +0.99) was demonstrated between ideal body weight and liver volume estimated by an ultrasonic scanning technique. Age-related changes in liver volume-to-body weight ratio could account for only 30% of differences in plasma theophylline clearance (1/h/kg) between children and adults. It is summized that increased hepatic mixed function oxidase activity is the major contributor to the higher plasma theophylline clearance in children.
mesh_terms: D000328:Adult; D000375:Aging; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008099:Liver / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D013806:Theophylline / Q000097:blood*; D014465:Ultrasonics
chemical_list: D013806:Theophylline