Brethine is a bronchodilator which is used in the treatment of symptoms associated with lung diseases such as asthma, emphysema, and bronchitis. Brethine has been proven effective at treating bronchospasms and the wheezing associated with bronchospasms.
Terbutaline is used to relieve and prevent attacks of asthma, including exercise-induced asthma. Asthma is a breathing problem caused by narrowing of the air passages (bronchial tubes) that allow air to move in and out of the lungs. These airways can be narrowed due to the accumulation of mucus, spasm of the muscles that surround them, or swelling of their linings due to the accumulation of fluid. Airway narrowing leads to shortness of breath, wheezing, and cough. Terbutaline dilates bronchial airways by relaxing the surrounding bronchial muscles. Terbutaline also can be helpful in patients with emphysema and chronic bronchitis when symptoms are partially caused by spasm of the muscles of the air passages. Terbutaline also is used for delaying premature labor by relaxing the uterine muscles that are responsible for expelling the fetus at delivery.