Bronchodilator
Bronchodilator, any of a group of drugs that expand the air passages (bronchial tubes) of the lungs . Bronchodilators are used to treat asthma, bronchitis, emphysema, and other diseases that affect the lungs. They relieve symptoms such as wheezing, shortness of breath, and coughing, and restore the patient’s ability to breathe comfortably. Bronchodilators work in various ways. Some, such as albuterol, affect the sympathetic nervous system, dilating the walls of the bronchial tubes. Others, such as theophylline, interfere with the action of certain enzymes or cells within the lungs, relaxing the constricted muscles of the airway. Many bronchodilators are inhaled through the mouth, especially those that provide immediate relief from an asthma attack. Some are taken orally in tablet or liquid form while others are injected into the skin. Inhaled bronchodilators are often prescribed with a dosage of 1 or 2 inhalations up to 4 times per day. A typical tablet dosage is 2 to 4 mg taken 3 to ...