Theophylline-controlled release dosage

Khullar R, Khar RK, Agarwal SP. Guar gum as a hydrophilic matrix for preparation of theophylline controlled-release dosage form. Indian J Fharm Set 1999 61(6) 342-345. 

Food may also affect the integrity of the dosage form, causing an alteration in the release rate of the drug. For example, theophylline bioavailability from Theo-24 controlled-release tablets is much more rapid whengiven to a subject in the fed rather than fasted state (Fig. 6). 

Theophylline improves long-term control of asthma when taken as the sole maintenance treatment or when added to inhaled corticosteroids. It is inexpensive, and it can be taken orally. Its use, however, also requires occasional measurement of plasma levels it often causes unpleasant minor side effects (especially insomnia) and accidental or intentional overdose can result in severe toxicity or death. For oral therapy with the prompt-release formulation, the typical dose is 3-4 mg/kg of theophylline every 6 hours. Changes in dosage result in a new steady-state concentration of theophylline in 1-2 days, so the dosage may be increased at intervals of 2-3 days until therapeutic plasma concentrations are achieved (10-20 mg/L) or until adverse effects develop. 

---