Asthma is a chronic respiratory disease in which sufferers experience significant constriction of the bronchioles, or small airways of the lungs. Mechanisms that instigate an asthma attack vary, including such triggers as cold air, exercise, pollutants, and substances to which the sufferer is allergic. Adrenaline plays an important role in alleviating symptoms of asthma.
The primary role of adrenaline in the body is to prepare it for "fight or flight"--that is to say, the hormone acts to help the human body deal with an emergency situation. In her book "Human Physiology," Dr. Lauralee Sherwood explains that adrenaline, produced by glands that sit on top of the kidneys and also called epinephrine, is released into the bloodstream whenever an individual senses emergency. As such, the body naturally releases high levels of adrenaline during an asthma attack.
As adrenaline floods the bloodstream during an asthma attack, it binds to receptors in the heart and lungs, notes Dr. Sherwood. This has several results, all of which help alleviate symptoms of asthma to a certain degree. The heart increases the rate and strength of its beat, helping to move blood through the lungs faster. Respiration rate increases as well, though that may be of limited utility in an acute asthma attack. Adrenaline also causes small airways to relax somewhat.
While the body releases adrenaline naturally during emergencies, researchers have determined that augmenting that natural adrenaline release with pharmaceutical adrenaline can help alleviate asthma symptoms even further. As an added bonus, inhaled adrenaline acts specifically on the lungs, opening airways without increasing heart rate as much as injected adrenaline would.
Although the body doesn't "overdose" on its own secreted epinephrine, it's certainly possible for individuals experiencing asthma attacks to overuse pharmaceutical epinephrine. Epinephrine inhalers are no longer recommended by organizations such as the National Heart Lung and Blood Institute. Not only can the side effects be quite serious, but the inhalers provide only very short-term relief, often leaving patients to experience asthma relapse within minutes of inhaler use.
YourLungHealth.org reports that concerns over the removal of epinephrine inhalers from the market exist on several levels. These inhalers were much less expensive than many pharmaceutical options, including short-acting beta agonist inhalers such as albuterol. Patients who can no longer find their accustomed inhaler on drug store shelves may go without treatment rather than see a physician.