EFFICACY OF ONCE-DAILY EXTENDED-RELEASE THEOPHYLLINE IN DECREASING THE USE OF INHALED BETA(2)-AGONISTS IN STABLE, MILD-TO-MODERATE ASTHMA PATIENTS

Background/Objective: The purpose of this study was to determine wheth er the addition of extended-release theophylline to the daily treatmen t regimen of inhaled beta(2)-agonist users would result in decreased u se of beta(2)-agonist while maintaining similar efficacy for treatment of asthma. Methods: This was a single-blind, multicenter (six sites) study. Sixty-one patients with a history of mild-to-moderate asthma tr eated with inhaled beta(2)-agonist were randomized to treatment with T heo-24 (anhydrous extended-release capsules) plus inhaled beta(2)-agon ist or placebo plus beta(2)-agonist. Patients kept daily symptom diari es, measured peak flow rates, recorded puffs of inhaled beta(2)-agonis t, and adverse events during a 4-week treatment period. Results: Fifty -five patients were included in the efficacy analysis. The primary eff icacy variable in this study was the mean number of puffs (adjusted fo r baseline differences) of beta(2)-agonist inhaled per day. In this st udy, the addition of theophylline to the daily regimen of inhaled beta (2)-agonist for 4 weeks significantly reduced the total daily dose of inhaled beta(2)-agonist at weeks 3 and 4 of treatment compared with pl acebo. The differences were significant at the P < .05 level. For pati ents in the theophylline group, the number of puffs decreased from an unadjusted mean of 9.81 at baseline to an adjusted mean of 6.78 after 4 weeks of treatment compared with 9.91 at baseline and 8.17 for the p lacebo group. There were no unexpected or serious adverse events. Conc lusions: In this study, the addition of once daily, extended-release t heophylline to the daily regimen of inhaled beta(2)-agonist for 4 week s significantly reduced the total daily dose of inhaled beta(2)-agonis t at weeks 3 and 4 of treatment compared with placebo, while maintaini ng acceptable asthma symptom scores.