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Oral Beta-2 Agonists
Inside the lungs, large airways branch into millions of tiny tubes called bronchioles. The ends of the bronchioles are small sacs (alveoli), which are so thin that air can pass through them into the blood. If the bronchioles are narrowed by inflammation or irritation, not as much air can get through them. However, the linings of the bronchioles have places (receptors) that attract beta-2 agonists. Stimulating the beta-2 receptors allows the bronchioles to widen so that more air can pass into the blood.
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Beta-2 agonists widen airways.
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For treating asthma, beta-2 agonists come in inhaled and oral forms. Oral beta-agonists must be absorbed in the digestive tract and travel through the blood to reach the lungs, so they do not begin to work as quickly as inhaled beta-2 agonists, which go straight to the lungs. They also may have more side effects, such as headaches, restlessness, and shaking.
Two types of oral beta-2 agonists are available currently. The immediate-release (short-acting) type works quickly and it can be used to stop an asthma attack, but it must be taken as much as 4 times a day. Extended-release (long-acting) oral beta-2 agonists are only taken twice a day, but they take longer to start working. Extended-release oral beta-2 agonists cannot stop an active attack?they are meant to prevent asthma flares.
Drugs in the class
Albuterol Oral Syrup
Albuterol Oral Tablets
Metaproterenol Tablets
Terbutaline Tablets
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