How do asthma inhalers work?

Asthma inhalers can contain different types of medications, all of which have an effect on the small airways in the lungs. The typical "rescue inhaler" that asthmatics are often prescribed for quick and short-term relief of symptoms like shortness of breath and wheezing contains a medication called albuterol. Albuterol binds to beta-adrenergic receptors on the surface of smooth muscle cells lining the small airways in the lungs; when this binding process occurs, the muscles relax and the airways become less constricted. Another frequently used class of medications in the treatment of asthma is inhaled corticosteroids, such as fluticasone. These medications work on the cells lining the same small airways to decrease local inflammation through a variety of mechanisms. As airway constriction and inflammation are the two main mechanisms in which asthma causes symptoms, these medications are the cornerstone of treatment. They have very limited systemic effects because they are inhaled and get effectively delivered to the place where they are needed. They have excellent safety profiles and provide asthmatic patients with significant relief when used correctly.