Genes and drugs

Genes affect how asthma patients respond to albuterol, the most commonly used asthma drug.

Genes affect how asthma patients respond to albuterol, the most commonly used drug for relief of acute asthma symptoms, or "attacks."

According to results of a new study of adults with mild asthma. Researchers in the Asthma Clinical Research Network (ACRN) of the National Heart, Lung, and Blood Institute (NHLBI), found that over time, how participants responded to daily doses of inhaled albuterol differed depending on which form of a specific gene they had inherited.

While a few weeks of regular use of albuterol improved overall asthma control in individuals with one form of the gene, stopping all use of albuterol eventually improved asthma control in those with another form of the gene.

The Beta-Adrenergic Response by Genotype (BARGE) trial is the first study of an asthma drug in patients selected according to their genotype, or which forms of a specific gene they have.

"If we can pinpoint which individuals will do better with a certain type of therapy, we can improve their lives more quickly and save them and the healthcare system the expense and risk of trying drugs that are less effective for them," Dr. Barbara Alving, was quoted as saying.

"This study helps put asthma at the forefront of pharmacogenetics," she added.

Asthma drugs are known to vary widely in their effects in different patients. Research suggests that genetics may play a role in these differences.

Albuterol relaxes the muscles in the airways and quickly opens up the air passages during an asthma attack, when airways are narrowed.

While all participants initially responded well to albuterol, after 16 weeks of daily use, those with the arginine genotype had poorer asthma control compared to their matched partners with the glycine genotype.

"This study highlights one of several variables that plays a role in how a medication will affect an individual," Dr. James Kiley, director of the NHLBI Division of Lung Diseases, was quoted as saying.

"It also serves as a reminder of how important it is for asthma specialists to regularly assess how their patients are responding to medications so they can modify their drug regimen as needed," he added.