Diskus and diskhaler: efficacy and safety of fluticasone propionate via two dry powder inhalers in subjects with mild-to-moderate persistent asthma

Background: Fluticasone propionate is a topically active glucocorticoid wit h potent antiinflammatory activity in the treatment of asthma. Objective: This study evaluated the safety and efficacy of fluticasone prop ionate administered via the Diskus and Diskhaler powder delivery devices in subjects with mild-to-moderate asthma. Methods: Fluticasone propionate (500 mu g 8 twice daily) or placebo was adm inistered via the Diskus and Diskhaler to 213 adolescent and adult asthma s ubjects in a randomized, double-blind, double-dummy, parallel-group study f or 12 weeks. Subjects were stratified according to baseline therapy of inha led corticosteroids or beta(2)-agonists alone. Subjects were dropped from t he study if they met predefined criteria for lack of efficacy. Results: Fluticasone propionate improved pulmonary function both in subject s previously treated with inhaled corticosteroids or beta(2)-agonists alone . At endpoint, fluticasone propionate significantly improved forced expirat ory volume in 1 second (P < .001), morning and evening peak expiratory flow (P < .001), and asthma symptom scores (P < .016), and significantly reduce d nighttime awakenings (P < .016; Diskhaler group only) and rescue albutero l use (P < .001). Overall, efficacy measurements for the Diskus and Diskhal er were similar. More placebo-treated subjects (34%) withdrew from the stud y due to lack of efficacy than subjects in the Diskus (5%) or Diskhaler (5% ) groups. The incidence and severity of adverse events were similar across groups. Measurement of plasma fluticasone propionate and cortisol concentra tions showed no apparent influence of device on systemic exposure. Conclusion: Fluticasone propionate powder, administered via the Diskus or D iskhaler inhalation devices, was well tolerated and effective in the treatm ent of mild-to-moderate persistent asthma.