Response of FeNO, Small Airway Dysfunction and Lung Heterogeneity to 2-week Montelukast Treatment in Asthmatic Children.

This study is a randomized, double-blind, placebo-controlled, cross-over study with a washout period of at least one week between each study period.

After an initial screening visit, subjects entered a screening period of one to two weeks to ensure clinical stability without medication, which means absence of daily asthma symptoms. Eligible subjects were randomized into either the treatment portion of the trial, in which subjects received montelukast (4 mg or 5 mg) or matching placebo monotherapy in a randomized manner. During each treatment period, which lasted 2 weeks, the study medication was administered between 8:00 and 9:00 A.M. Short acting bronchodilator (for severe symptoms) was permitted during the study period but was withheld 24 hours prior to bronchodilator challenge test.

Inclusion criteria

will be mild persistent asthma children old enough to cooperate on performing pulmonary function testing, children with no respiratory symptoms 4 weeks prior to the beginning of the study. Exclusion criteria will be the following: respiratory symptoms including cough, wheezing, dyspnea, or shortness of breath, presence of acute or chronic upper respiratory infections, anatomical nasal disorders (ex, nasal polyps, septum deviation, etc.), previous or current specific immunotherapy, use of systemic corticosteroids, or admission or visit of the emergency department during the previous 4 weeks.

Inclusion criteria

• children diagnosed with mild persistent asthma patients based on the GINA guidelines
• children old enough to cooperate in performing pulmonary function testing
• legal guardians who sufficiently listen to the purpose and voluntarily agree with the participation to sign a written consent approved by IRB
• children with no respiratory symptoms 4 weeks prior to the beginning of the study
• children without chronic respiratory symptoms.

Exclusion criteria

• presence of acute or chronic upper respiratory infections, anatomical nasal disorders (ex, nasal polyps, septum deviation, etc.), previous or current specific immunotherapy.
• use of systemic corticosteroids in past 4 weeks.
• admission or visit of the emergency department in past 4 weeks.