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.

Inclusion Criteria:

1. Male or female from birth to 48 months of age, inclusive, whose parent(s) or legal
guardian(s) provide written informed consent prior to study participation and are
willing to comply with study procedures.

2. Subject experiencing acute bronchospasm requiring a bronchodilator and who have a
history of wheezing.

Exclusion Criteria:

1. Subject with a severe illness that, in the opinion of the Investigator, could
jeopardize subject safety.

2. Subject received ≥ 8 puffs (MDI) of a beta-2 agonist or 2.5 mg of nebulized
levalbuterol, or albuterol 5.0 mg within 4 hours prior to ED or physician's office
admittance.

3. Subject received ipratropium within 4 hours prior to ED or physician's office
admittance.

4. Subject who participated in an investigational drug study within 30 days prior to
enrollment, or who previously participated in the current study.

5. Subject with a known sensitivity to levalbuterol or racemic albuterol or any of the
excipients contained in any of these formulations.

6. Subject using any prescription drug (including beta-blockers) with which levalbuterol
or racemic albuterol sulfate administration is contraindicated.

7. Subject with a history of clinically significant abnormalities that could interfere
with the metabolism or excretion of the study medication (eg, renal, hepatic,
metabolic, or endocrine abnormalities).

8. Subject with a history of cancer.