title: Correlation of serum and saliva theophylline concentration after administration of a sustained release preparation.
abstract: The correlation between serum and saliva levels of theophylline was investigated in seven healthy volunteers after multiple dose administration of a low dose (300 mg/day) and a high dose (900 mg/day) of a sustained release theophylline preparation (Theo-Dur). Tablets were taken for five days, at 8 a. m. and 8 p. m. and a last dose was taken on Day 6 at 8 a. m. Fourteen serum and saliva samples were collected simultaneously during the dosing period and for up to 32 h after the last dose. On the 300 mg/day regimen the level in saliva was 55.3% of the serum level, with an overall variability of 6.7% and an intrasubject variability of 10.5%. After 900 mg/day, the saliva concentration was 55.5% of the serum concentration, with an overall variability of 7.6% and an intrasubject variability of 12.7%. A good correlation was found between both determinations (r = 0.99), which suggests that saliva levels could be used to monitor theophylline after administration of a sustained release tablet.
mesh_terms: D000042:Absorption; D000328:Adult; D003692:Delayed-Action Preparations; D006801:Humans; D011485:Protein Binding; D012463:Saliva / Q000032:analysis*; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline