title: Monitoring children on sustained-release therapy by salivary theophylline levels.
abstract: The serum-saliva theophylline level ratio was measured in 19 chronically asthmatic children after their conditions were stabilized on a sustained-release theophylline preparation. Simultaneous serum and saliva samples were collected at 0, 4, 6, and 10 hours after theophylline dose and measured by high-pressure liquid chromatography. The mean ratio for the group of 1.52 +/- 0.64 approximated the mean ratio from previous reports. However, the correlation coefficient (r = .80) was lower, and the interpatient and intrapatient variability (25% and 23%) much higher, than in previous reports. The possible mechanism of these findings in relation to sustained-release preparations are discussed. These data question the use of salivary theophylline determinations to monitor therapy. Dosage should be based on serum measurements.
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000188:drug therapy*; D002648:Child; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D008297:Male; D012463:Saliva / Q000032:analysis*; D013806:Theophylline / Q000032:analysis* / Q000097:blood / Q000627:therapeutic use
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline