Unless they are taken at unacceptably frequent intervals, conventional rapid-release @entity2544 tablets and liquids produce excessive serum concentration fluctuations, particularly in @entity1 with rapid elimination. Slow-release formulations provide more stable serum concentrations with longer dosing intervals if absorbed completely, consistently, and at a sufficiently slow rate and thus have the potential to improve efficacy and compliance. However, there are clinically important differences in the extent and rate of absorption among the 15 slow-release formulations available under 29 brand names in the United States. Fluctuations in steady-state serum concentrations are a function of the absorption rate of the product, the elimination rate of the @entity1 , and the dosing interval. In @entity1 with slow elimination, clinically relevant differences among formulations are not apparent with twice-daily dosing. Among @entity1 with more rapid elimination, however, available data for only two products demonstrate sufficiently slow absorption to justify routine twice-daily use without excessive fluctuations. More rapidly absorbed formulations must be administered at 8-hour intervals in such @entity1 to prevent breakthrough in asthmatic symptoms before the next dose, despite promotional claims to the contrary. Current products approved for "once-a-day" dosing are clinically inadequate because of incomplete or erratic absorption or excessive serum concentration fluctuations. Lastly, food intake induces dose dumping of potentially toxic amounts of @entity2544 from @entity2544 and greatly impairs absorption from Theo-Dur Sprinkle capsules but has no important effect on Theo-Dur tablets. The effects of food on most other @entity2544 products are not known.

XXXX product and dosing interval selection for chronic asthma.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity2544 :: ('MESH:D013806', 'Chemical') :: ['theophylline', 'Theo-24']
@entity2544 :: (MESH:D013806,Chemical) :: ['Theophylline']
