The Effect of Montelukast on Difficulty in Breathing After Exercise in Pediatric Patients (MK0476-377)(COMPLETED)

A Double-Blind, Placebo-Controlled, Multicenter, Crossover Study to Evaluate the Effects of a Single Oral Dose of Montelukast, Compared With Placebo, on Exercise-Induced Bronchoconstriction (EIB) in Pediatric Patients Aged 4 to 14 Years

This study will see if there is a change in breathing after exercising when the child receives study drug ( montelukast or placebo). Breathing will be measured by a spirometer before exercising and measured again several times after exercising.

Inclusion Criteria:

• The child is 4 years to 14 years of age
• The child is a non smoker
• The child has exercise-induced bronchoconstriction (EIB)

Exclusion Criteria:

• The child has active or chronic breathing disease, other than asthma
• The child has required insertion of a breathing tube for asthma
• The child had major surgery within the last 4 weeks
• The child is currently in the hospital
• The child has or had an upper respiratory tract infection within the last 2 weeks
• The child has been hospitalized or visited the emergency room or had a change in their medication for asthma within the last 4 weeks
• The child has been in a research study in the last 4 weeks
• The child has stomach, brain, heart, kidney or liver disease
• The child drinks more that 4 caffeinated drinks a day