Many experts question the safety of using long acting beta agonists (LABAs) in treating asthma. Particularly, many feel as though African-Americans who use LABAs are at an increased risk for exacerbating their asthma symptoms. One idea is that allelic variation in the Arg16Gly gene could be causing pharmacogenetic variability that is disproportionately affecting African-Americans.
This study tested this hypothesis by comparing the asthmatic symptoms of African-American patients using LABAs with an inhaled corticosteroid (ICS) to African-American patients using tiotropium and an ICS. Each patient also underwent genotyping to gauge the effect of the Arg16Gly gene. The results of the study showed that use of LABAs with an ICS did not exacerbate asthmatic symptoms any more than the use of tiotropium with an ICS. The study also showed that the Arg16Gly gene did not correlate to an increase in asthmatic symptoms, thus debunking the idea of pharmacogentic variability. Overall, the study showed that there is no difference in the worsening of asthma symptoms between LABAs and tiotropium.
This study shows the importance of researching preconceived notions about discrepancies in how certain patient populations handle medications. Without this research, some patients could receive sub-optimal therapy because of an untested yet widely accepted idea.