title: Evaluation of the effect of food on the absorption of sustained-release theophylline and comparison of two methods for serum theophylline analysis.
abstract: Fifteen healthy volunteers took part in a study to investigate the effect of food on the bioavailability of a slow-release formulation of theophylline. Serum theophylline levels were measured every two hours for ten hours after a single oral dose of 500 mg of theophylline. Serum levels were significantly higher after the dose was taken on an empty stomach; however, serum levels were significantly higher 10 hours later when the dose was taken after a standard meal. Despite these differences, eating had no overall effect on theophylline bioavailability. Two analytic methods for measuring serum levels of theophylline were compared, and it was found that fluorometry could measure lower levels and was therefore more precise than an enzyme immunoassay method, which is probably due to the complete automation and reduced interference of bilirubin and hemoglobin.
mesh_terms: D000328:Adult; D003692:Delayed-Action Preparations; D005502:Food; D006801:Humans; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline