The effect of steroids on theophylline absorption.

The effect of hydrocortisone on plasma theophylline concentrations was evaluated in 20 patients suffering from chronic bronchitis or stable bronchial asthma. Choline theophyllinate (400 mg) was orally administered every 12 h for 8 days and blood samples were taken every 2 h during the day for the measurement of theophylline concentrations. Intravenous bolus injections of 500 or 1000 mg hydrocortisone on day 5 or day 7, respectively, did not significantly alter plasma theophylline concentrations.

A single-blind crossover study of two different slow release theophylline preparations.

In a single-blind crossover study, two slow release theophylline preparations were evaluated in 18 patients with chronic bronchitis or asthma without cardiac, renal or liver disease. After randomization into two groups, patients were treated, in a crossover study design, with 600 mg choline theophyllinate or 300 mg anhydrous theophylline administered orally every 12 h for 7 days. A 2-day washout period separated the two periods of treatment evaluation.