An Evaluation of Levalbuterol HFA in the Prevention of Exercise-Induced Bronchospasm

BACKGROUND: Exercise-induced bronchospasm (EIB) affects up to 90% of all patients with asthma. OBJECTIVE: This study evaluated the ability of levalbuterol hydrofluoroalkane (HFA) 90 μg (two actuations of 45 μg) administered via metered dose inhaler (MDI) to protect against EIB in mild-to-moderate asthmatics. METHODS: This was a randomized, double-blind, placebo-controlled, two-way cross-over study. Patients with asthma (n = 15) were ≥18 years, had a ≥6-month history of EIB, ≥70% baseline predicted forced expiratory volume in 1 second (FEV(1)), and a 20% to 50% decrease in FEV(1) after treadmill exercise challenge using single-blind placebo MDI. Levalbuterol or placebo was self-administered 30 minutes before exercise. Treatment sequences were separated by a 3-to 7-day washout period. Spirometry was performed predose, 20 minutes postdose/pre-exercise, and 5, 10, 15, 30, and 60 minutes post-exercise. The primary endpoint was the maximum percent decrease in FEV(1) from baseline (postdose/pre-exercise). The percentage of protected (≤20% decrease in post-exercise FEV(1)) patients was also assessed. RESULTS: Levalbuterol had significantly smaller maximum percent post-exercise decrease in FEV(1) compared with placebo (LS mean ± SE; −4.8% ± 2.8% versus −22.5% ± 2.8%, respectively). For levalbuterol, 14/15 (93.3%) patients had <20% decrease in post-exercise FEV(1) compared with 8/15 (53.3%) for placebo (p = 0.0143). Treatment was well tolerated. CONCLUSION: Levalbuterol HFA MDI (90 μg) administered 30 minutes before exercise was significantly more effective than placebo in protecting against EIB after a single exercise challenge and was well tolerated. CLINICAL IMPLICATIONS: Levalbuterol HFA MDI when administered before exercise was effective in protecting adults with asthma from EIB.