What They Are: Long acting beta agonists, or LABAs for short, are a class of asthma medicines commonly known as bronchodilators. LABAs' effects last for 12 hours or more, which is why they are called "long-acting."
At one time, these long-acting bronchodilators were used as an alternate to inhaled steroids. However, due to safety concerns, they are currently only recommended to be used as add-on therapy in combination with inhaled steroids, and only in people who have not been able to achieve adequate control with steroids alone.
How They Work: The primary action of long-acting beta agonists is to relax the smooth muscles in the walls of the airways. They do so by stimulating beta receptors that act against bronchoconstriction. Their effects can last as long as 12 hours after a single dose, but when they are used regularly, their length of action tends to be closer to 5 hours.
The Effects: When used in conjunction with low to moderate doses of inhaled steroids, LABAs are useful as a daily controller medicine and have the following benefits:
- improve lung function
- decrease asthma symptoms
- reduce asthma attacks and use of quick-relief inhalers in most patients
What they don't do, however, is have any effect on the inflammatory process that causes asthma. Besides the uses described above, LABAs can also be prescribed to prevent symptoms in people who have exercise-induced asthma.
Examples: There are currently 2 LABA asthma medicines in use:
LABAs are generally administered in either a metered dose inhaler or in a dry powder inhaler. In addition, LABAs are used in combination with inhaled steroids in inhalers such as Advair.
Comparison to Inhaled Steroids: Long-acting bronchodilators treat some, but not all, of the asthma symptoms relieved by inhaled steroids. So, they are not as effective a medicine when used alone. Used as an adjunct to inhaled steroids, though, they can be quite useful in controlling moderate to severe persistent asthma.
Other Important Facts: As a result of studies done in 2006 that showed there was a slight increase in deaths in people using LABAs, the FDA decided to require a "black box warning" be placed on the prescribing information and patient handouts for all LABA asthma medicines. A black box warning is used to warn healthcare professionals and patients that there may be a risk of serious side effects when these medicines are used. It doesn't mean the medicine should not be used, but the doctor and patient should carefully weigh the possible risks against the potential benefits when deciding to use a long acting beta agonist.
In Summary: Long-acting beta agonists can be an important component of an asthma management plan for people who are not able to achieve asthma control with an inhaled steroid alone. As long as you and your doctor watch carefully for any worsening of asthma symptoms or unexpected effects, LABAs should be safe to use.
