“Asthma is a disease characterized by an increased responsiveness of the trachea and bronchi to various stimuli and manifested by a widespread narrowing of the airways that changes in severity either spontaneously or in response to therapy.” The airway narrowing is the end result of some combination of bronchial muscle contraction, tissue inflammation, mucosal edema, and luminal occlusion by cellular debris and thickened secretions. During the last decade, basic and applied research has shed light on the physiology of the above changes and has led to breakthroughs in therapy and the more rational use of older and newer therapeutic agents, both separately and together
