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 whether the addition of extended-release theophylline to the daily treatment regimen of inhaled beta 2-agonist users would result in decreased use 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 treated with inhaled beta 2-agonist were randomized to treatment with Theo-24 (anhydrous extended-release capsules) plus inhaled beta 2-agonist or placebo plus beta 2-agonist. Patients kept daily symptom diaries, measured peak flow rates, recorded puffs of inhaled beta 2-agonist, and adverse events during a 4-week treatment period.

RESULTS

Fifty-five patients were included in the efficacy analysis. The primary efficacy variable in this study was the mean number of puffs (adjusted for baseline differences) of beta 2-agonist inhaled per day. In this study, 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 placebo. The differences were significant at the P < .05 level. For patients 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 placebo group. There were no unexpected or serious adverse events.

CONCLUSIONS

In this study, the addition of once daily, extended-release 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 placebo, while maintaining acceptable asthma symptom scores.