Bronchodilator, << `brong` koh dy LAY tuhr or `brong` koh duh LAY tuhr, >> is any of a group of drugs that open up the small breathing tubes in the lungs. These tubes are called bronchioles. Doctors prescribe bronchodilators to treat respiratory illnesses, including asthma, bronchitis, and emphysema. The drugs relax the muscles in the bronchioles, thereby expanding the tubes and making breathing easier. This can relieve such symptoms as coughing and wheezing.
Bronchodilators may be taken by mouth as a tablet, capsule, or syrup. Sometimes they are injected. But most often, they are inhaled directly into the lungs. Many patients with asthma use metered-dose inhalers. These devices consist of a mouthpiece and a container called a canister. The canister holds bronchodilators in the form of a liquid or a fine powder. While holding the mouthpiece in the mouth, the patient pushes a spring on top of the canister, releasing a certain amount of the bronchodilator. As the patient inhales, the drug enters the bronchioles.
Bronchodilators can produce several side effects. The drugs can increase the heart rate and blood pressure. They cause some patients to become restless or dizzy.
Albuterol, metaproterenol, and terbutaline are among the most widely used bronchodilators, especially by people with asthma. Another bronchodilator, theophylline, was once the primary drug for treating asthma and emphysema. The bronchodilator epinephrine was frequently given by injection for severe asthma attacks in the past. Today, doctors use epinephrine injections mainly in life-threatening emergencies when the patient cannot use an inhaled drug.
