Patient description: The patient is a 15-year-old boy with asthma diagnosed a year ago. He presents with shortness of breath, chest tightening and cough. According to his mother, he didn't respond to the usual corticosteroid inhaler. He was admitted to the emergency department with diagnosis of severe asthma exacerbation. He is a candidate for general corticosteroid therapy. Spirometry revealed a forced expiratory volume in the first second (FEV1) of 60% of the predicted. His past medical history is non-significant. His family history is significant for asthma in his mother and his uncle. He used to be treated with combination of inhaled corticosteroids and Zafirlukast.

Clinical trial eligibility criteria: eligible ages (years): 4.0-11.0,  Asthma Generally healthy. 2. Male and female mild-to-moderate asthma patients. 3. Aged 4 yr (upon screening). 4. Female patients must be premenarchal upon Visit-1, and those who become menarchal during the study must use an accepted method of contraception including abstinence. 5. A documented history of asthma, for at-least 6-months prior to Screening, requiring inhaled B-adrenergic agonists, with or without inhaled corticosteroids for asthma symptom control. 6. Satisfying asthma stability criterion, defined as no changes in asthma therapy and no asthma-related hospitalization or emergency room visits, over the 4 weeks prior to Screening. 7. Being able to withhold treatment with inhaled bronchodilators and/or restricted medications for the minimum washout periods indicated in Appendix II, for the purpose of conducting clinical visits. 8. Having a baseline forced expiratory volume in 1 second (FEV1), that is 50.0-100.0% of predicted values at the screening (Screening Baseline FEV1). 9. Demonstrating a greater than or equal to 12.0% reversibility in the Reversibility Test, at 30 min after inhaling 2-4 puffs (180-360 mcg) of Ventolin-HFA. 10. Demonstrating correct use of metered-dose inhaler (MDIs), and acceptable performance in the FEV1 measurements. 11. Has properly consented, with a parent or a legal guardian, to participate in this study  Any current or past significant medical conditions that, according to the investigator, might affect pharmacodynamic response to the study drugs, such as significant systemic or respiratory diseases (e.g., cystic fibrosis, bronchiectasis, emphysema, nonreversible pulmonary diseases), other than asthma. 2. Concurrent clinically significant cardiovascular, hematological, renal, neurological, hepatic, and endocrine disorders, or psychiatric diseases. 3. Known intolerance or hypersensitivity to any component of the MDI formulation (e.g., albuterol, HFA-134a, oleic acid, ethanol). 4. Recent upper (within 2 weeks) or lower (within 4 weeks) respiratory tract infection before screening. 5. Recent (within 4 weeks) use of systemic (or oral) corticosteroids and B-adrenergic bronchodilators; or recent (within 2 weeks) use of monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), or B-blockers; before the Screening. 6. Having been on other investigational drug/device studies in the last 30 days prior to screening. 7. Known or reasonably suspected alcohol/drug abuses. 8. Having smoked within the last 12 months