title: Pharmacokinetics of a sustained-release theophylline formulation.
abstract: 1 Plasma theophylline concentrations following administration of sustained-release (SR) theophylline tablets were determined in ten healthy volunteers using a dose of 190 mg or 380 mg 12 hourly. 2 The plasma theophylline levels during the first 12 h period confirmed the sustained-release formulation characteristics, with the plasma drug concentrations reaching a plateau for the last 6 hours. 3 During the fifth 12 h dosing period the mean maximum and minimum plasma theophylline concentrations were 7.25 and 4.30 microgram/ml after 190 mg SR theophylline 12 hourly (n = 6) and 12.96 and 7.36 microgram/ml after 380 mg 12 hourly (n = 5), although there was marked between-subject variation in plasma theophylline concentrations. 4 One subject withdrew from the study due to side effects, which were more common when the higher dose of SR theophylline was given.
mesh_terms: D000328:Adult; D001682:Biological Availability; D003692:Delayed-Action Preparations; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D013806:Theophylline / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D013806:Theophylline