Food-induced changes in theophylline absorption from controlled-release formulations. Part II. Importance of meal composition and dosing time relative to meal intake in assessing changes in absorption.

Theo-24 (G. D. Searle & Co.) is an ultra-slow-absorbing formulation of theophylline suitable for once-a-day dosing in slow and normal metabolizers of theophylline. Relative to fasting conditions, increased rate and extent of theophylline absorption occur when this product is administered immediately after a breakfast with a high fat content. Our study demonstrated that factors such as meal composition (fat content) or dosing time relative to meal intake can modify the high fat-induced changes in absorption. For consistent, slow absorption, patients taking high doses (greater than or equal to 900 mg) of Theo-24 once a day should take this product in the morning under fasting conditions or with a breakfast containing less than or equal to 10 gm fat. If a high-fat breakfast (greater than 55 gm fat) is taken, then Theo-24 should be administered at least 1 hour before the meal.