A Study of Levalbuterol Tartrate HFA Inhalation Aerosol Metered Dose Inhaler (MDI) in Pediatric Subjects

This is a study to determine the safety and tolerability of cumulative dosing with levalbuterol tartrate HFA inhalation aerosol MDI using a valved holding chamber and facemask in pediatric subjects birth to ≤ 48 months of age with acute bronchospasm. It is a randomized, double-blind, parallel-group, multicenter, trial of 3 doses of levalbuterol tartrate HFA inhalation aerosol MDI in pediatric subjects birth to ≤ 48 months of age who present to either the Emergency Department (ED) or their physician's office with an acute bronchospasm. Subjects presenting to the ED or physician's office with an acute bronchospasm must have a history of reactive airways disease, based on subjects' parent/guardian report. Eligible subjects whose parent(s) or legal guardian(s) provide written informed consent to participate will be randomized to 1 of 2 treatments. Treatment 1 consists of 3 doses, with each dose comprised of 8 puffs (4 puffs of levalbuterol tartrate HFA inhalation aerosol 45 mcg/puff plus 4 puffs of placebo HFA \[cumulative dose of 540 mcg levalbuterol tartrate HFA inhalation aerosol\]); Treatment 2 consists of 3 doses, with each dose comprised of 8 puffs of levalbuterol tartrate HFA inhalation aerosol 45 mcg/puff (4 puffs of levalbuterol tartrate HFA inhalation aerosol 45 mcg/puff plus 4 puffs of levalbuterol tartrate HFA inhalation aerosol 45 mcg/puff \[cumulative dose of 1080 mcg of levalbuterol tartrate HFA inhalation aerosol\]). For each Treatment, study medication will be administered every 20 minutes over a period of 1 hour for three doses.