Each participant will receive three inhalers with their assigned medication. One inhaler will be used twice daily throughout the study. The other two inhalers will be used consecutively on an as-needed-basis as rescue medication. Study visits will occur at Weeks 8, 16, 24, 32, 40, and 48. A physical examination, blood collection, and lung function and airway pressure testing will occur at selected visits. Questionnaires to assess quality of life and asthma control will also be completed. A methacholine challenge test will be completed at some study visits. This test artificially triggers an asthma attack to determine the severity of an individual's asthma. Throughout the study, participants will record asthma symptoms and rescue medication usage in a daily diary.