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FDA advisory panel strikes down common asthma drugs

An advisory panel yesterday recommended that the Food and Drug Administration (FDA) strip two popular asthma drugs—GlaxoSmithKline's Serevent and Schering Plough's Foradil—from the market. These drugs belong to a class of compounds called long acting β2 -agonists (LABAs), which have been linked to increased risk of fatal asthma attacks.

Serevent and Foradil were approved for use in 1994 and 2001, respectively, but two years ago the FDA ordered the companies to put black box warnings on them alerting consumers to their potential dangers.

Two general classes of drugs are used to treat asthma: relievers and controllers. Relievers work fast to increase airflow to the lungs, but their effects wear off quickly. The commonly prescribed albuterol, for example, provides a quick fix for an asthma attack.

Controllers, on the other hand, work gradually and must be taken on a regular basis to control the root of the disease. LABAs are controllers, which are effective for as long as 12 hours.  According to National Institutes of Health (NIH) guidelines, LABAs should only be taken with inhaled corticosteroids (ICS), which help to reduce inflammation and mucus buildup in the airways.

"They are meant to be used as add-ons controllers with ICS," says Mark Moss, a pediatric allergist at the University of Wisconsin School of Medicine and Public Health in Madison. If LABAs are not combined with ICS, the risk of death increases, he adds.

Yet, as members of the FDA advisory panel pointed out, many doctors still prescribe LABAs without steroids and, even when they do prescribe the combo, many patients fail to use the steroids or stop using them if they feel better. Six million adult and pediatric asthma patients in the U.S. are currently taking LABAs; approximately 120,000 of them (2 percent) take Serevent and Foradil, according to FDA  spokesperson Karen Riley.

"There is good evidence that for people with asthma taking long acting β2 –agonists [LABAs] without corticosteroids, there is an increased risk of serious asthmatic events," says Sean Hennessy, a pharmacologist at the University of Pennsylvania and a member of the advisory panel.  "It's hard to get people to keep taking inhaled corticosteroids," he adds, noting that patients must always use them with Serevent and Foradil to prevent potentially deadly airway swelling.

The panel yesterday also recommended that two other popular asthma Rxs, Advair and Symbicort, continue to be sold. These meds are also LABAs but steroids are mixed into them. The FDA approved Advair in 2001 and Symbicort in 2006.

On a related note, researchers published a study in the current issue of the journal Evidence-Based Child Health suggesting that LABA's, even when taken with ICS therapy, provide no net benefit to children with the asthma. A team of researchers led by Amy Plint, an emergency physician at the Children’s Hospital of Eastern Ontario, concluded that though LABAs with steroids may improve lung function, they do not appear to reduce asthma symptoms in children over the age of four.

Some 300 million people worldwide and 20 million in U.S. suffer from asthma, a disease marked by chronic inflammation of the airways and characterized by symptoms including coughing, wheezing, and difficultly breathing that tend to flare up in response to exercise or exposure to irritants such as .

Image credit ©iStockphoto.com/Tulay Over

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