Bronchodilators: Relieving Asthma Symptoms

One type of medication is used by almost all people with asthma: a bronchodilator. Short-acting bronchodilators are used only as needed as asthma “rescue” medications, while long-acting bronchodilators are used every day to control asthma. Bronchodilators open up the bronchial tubes so that more air can move through. Bronchodilators also help clear mucus from the lungs. As the airways open, the mucus moves more freely and can be coughed out (expelled) more easily.

What types of bronchodilators stop asthma symptoms?

The three types of bronchodilators are 1) beta-agonists, 2) anticholinergics, and 3) theophylline. These bronchodilators are available in inhaled, tablet, liquid, and injectable forms, but the preferred method of taking the beta-agonists and anticholinergics is by inhalation.

What are the short-acting bronchodilators?

Short-acting bronchodilators are called "quick acting," "reliever," or "rescue" medications. These bronchodilators relieve asthma symptoms very quickly by opening the airways. The rescue medications are best for treating sudden asthma symptoms. The action of inhaled bronchodilators starts within minutes after inhalation and lasts for 2 to 4 hours. Bronchodilators in asthma inhalers are also used 15-20 minutes before exercise to prevent exercise-induced asthma.

For more information, see WebMD’s article on Asthma Inhalers.

Short-acting bronchodilators can be used in an asthma nebulizer (breathing machine) to treat an asthma attack at home. The problem with oral forms of bronchodilators compared with asthma inhalers is that they tend to have more side effects because they are in higher doses and travel throughout the bloodstream to get to the lungs. Contrary to this, bronchodilators delivered with asthma inhalers go directly into the airways and have fewer side effects.

For in-depth information, see WebMD’s article on Asthma Nebulizers (Breathing Machines).

Overuse of short-acting bronchodilators, whether in asthma inhalers, in tablets, or in liquid, is a sign of unstable asthma that needs treatment that is more aggressive. If you need to use your short-acting bronchodilators more than twice a week, talk with your doctor about improving your asthma controller therapy.

Short-acting bronchodilator inhalers available in the United States include:

• Albuterol (Proventil HFA, Ventolin HFA, AccuNeb, also available as a generic solution for nebulizers)
• Alupent (Metaproterenol, available as a generic solution for nebulizers, see below)
• Combivent (combines a beta-agonist and an anticholinergic, see below)
• DuoNeb (combines a beta-agonist and an anticholinergic, see below)
• Maxair
• Xopenex

What are the long-acting bronchodilators for relieving asthma symptoms?

The long-acting bronchodilators are used to provide control -- not quick relief -- of asthma. These bronchodilator inhalers last for at least 12 hours.  Those containing formoterol begin their action within a few minutes, while those containing salmeterol take up to 45 minutes to begin their action.

Advair, Symbicort, Serevent, and Foradil inhalers include long-acting bronchodilators that are used twice a day. Long-acting bronchodilators probably increase the risk of asthma-related death when used regularly without an inhaled steroid.  For details, see their black-box warning.