title: Serum profile and bioavailability of a controlled-release theophylline formulation for once-daily use: comparison with a 12-hr preparation.
abstract: Two controlled-release theophylline drugs, T-D (Theo-Dur tablets) administered 12-hourly, and preparation U (Uniphyl tablets) once daily, given in 7-day sequences in daily 800-mg doses, produced comparable steady-state serum profiles in nonsmoking adults with asthma, chronic bronchitis, or both, showing acceptable theophylline clearances. With either regimen, mean serum levels were within the 10-20 mcg/ml range at most time points, never falling below 9 mcg/ml or exceeding 20 mcg/ml. Analyses of variance for troughs, peaks, trough-peak fluctuations and AUCs (0,24) could not differentiate between drugs. The theophylline in each was fully bioavailable relative to immediate-release theophylline. Side effects, least prevalent with Drug U, were of the "minor nuisance" variety. These data indicate the suitability of Drug U for once-daily prescription.
mesh_terms: D000328:Adult; D000368:Aged; D001249:Asthma / Q000097:blood / Q000188:drug therapy; D001682:Biological Availability; D001991:Bronchitis / Q000097:blood / Q000188:drug therapy; D002986:Clinical Trials as Topic; D003692:Delayed-Action Preparations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013607:Tablets; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood*; D013997:Time Factors
chemical_list: D003692:Delayed-Action Preparations; D013607:Tablets; D013806:Theophylline