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

Fluticasone propionate is a topically active glucocorticoid with potent antiinflammatory activity in the treatment of asthma. This study evaluated the safety and efficacy of fluticasone propionate administered via the Diskus and Diskhaler powder delivery devices in subjects with mild-to-moderate asthma. Fluticasone propionate (500 μg twice daily) or placebo was administered via the Diskus and Diskhaler to 213 adolescent and adult asthma subjects in a randomized, double-blind, double-dummy, parallel-group study for 12 weeks. Subjects were stratified according to baseline therapy of inhaled corticosteroids or β 2-agonists alone. Subjects were dropped from the study if they met predefined criteria for lack of efficacy. Fluticasone propionate improved pulmonary function both in subjects previously treated with inhaled corticosteroids or β 2-agonists alone. At endpoint, fluticasone propionate significantly improved forced expiratory volume in 1 second ( P < .001), morning and evening peak expiratory flow ( P < .001), and asthma symptom scores ( P ≤ .016), and significantly reduced nighttime awakenings ( P = .016; Diskhaler group only) and rescue albuterol use ( P < .001). Overall, efficacy measurements for the Diskus and Diskhaler were similar. More placebo-treated subjects (34%) withdrew from the study 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 concentrations showed no apparent influence of device on systemic exposure. Fluticasone propionate powder, administered via the Diskus or Diskhaler inhalation devices, was well tolerated and effective in the treatment of mild-to-moderate persistent asthma.