Interaction between nutrition and theophylline metabolism in children.
The influences on theophylline metabolism are multifactorial, resulting in significant inter- and intrapatient variability in drug responsiveness. Clinical investigations with adult patients have demonstrated the influence of diet on theophylline metabolism following a single drug dose. We have undertaken this study to examine the effect of nutritional factors on theophylline pharmacokinetics in 14 asthmatic children receiving the drug on a chronic basis. For 12-day periods each patient received three separate diets with different proportions of protein and carbohydrate but with constant fat and caloric intake. Significant differences were detected for theophylline half-life, apparent volume of distribution, and metabolic clearance rate. The high-protein diet markedly shortened the drug-elimination half-life relative to a normal diet, and high carbohydrate significantly increased it (both p less than 0.001). Other kinetic parameters confirmed this pattern. Our findings in children clearly establish that nutritional factors have a significant environmental influence on theophylline metabolism during the drug's steady-state pharmacokinetics.
D000293:Adolescent; D001249:Asthma / Q000188:drug therapy; D002648:Child; D004032:Diet; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007700:Kinetics; D008297:Male; D008657:Metabolic Clearance Rate; D013806:Theophylline / Q000378:metabolism* / Q000627:therapeutic use
D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D013806:Theophylline