Clinical comparability of albuterol delivered by the breath-actuated inhaler (Spiros (R)) and albuterol by MDI in patients with asthma

Study objective: This study compares the efficacy and safety of one and two actuations of albuterol sulfate powder delivered via a breath-actuated, ef fort-assisted, investigational inhaler (Spiros(R), Dura Pharmaceuticals, In c) and albuterol delivered via a conventional propellant-driven metered dos e inhaler (Ventolin(R) Glare, Inc). Design: Randomized, double-blind, placebo-controlled, 5-way crossover study . Participants: Sixty patients with mild-to-moderate asthma (FEV1 59% predict ed) were enrolled and 44 completed the study. Measurements and results: FEV1 values over 6 hours were analyzed by ANCOVA and the Finney relative potency model. The relative potency of the inhalers (albuterol MDI: albuterol DPI) was 1.132 (90% CI, 0.680 to 2.252) indicati ng 1.132 actuations of albuterol MDI provided the same bronchodilation as o ne actuation of albuterol DPI. ANCOVA analyses further indicated that there were no significant differences between the two delivery systems with resp ect to FEV1, FVC, FEF25-75% or PEF. Both inhalers had similar effects on se rum potassium levels, QTc interval, blood pressure, and heart rate. Conclusions: In patients with mild-to-moderate asthma in this study, the al buterol DPI was determined to be therapeutically comparable to albuterol MD I in the delivery of one and two actuations of albuterol.