For those with asthma, using too much albuterol can be harmful. A study by researchers at the University of Arizona Mel and Enid Zuckerman College of Public Health and the Arizona Respiratory Center examined albuterol overuse among participants with mild asthma and found that most overuse unexpectedly occurred on symptom-free days rather than symptom days. Furthermore, those who overused albuterol were twice as likely to have evidence of clinically relevant depression. The study was published in The Journal of Allergy and Clinical Immunology: In Practice.
[Photo: Dr. Joe Gerald]
Albuterol overuse, three or more canisters per year, is associated with poor asthma control and frequent exacerbations. The researchers used daily diary reports to look at albuterol use on symptom and symptom-free days to identify patterns of albuterol overuse. They also measured controller medication use to estimate adherence levels.
These secondary analyses used data from the Trial of Asthma Patient Education (TAPE). Based on albuterol use of 80 percent or more on symptom days and less than 20 percent on symptom-free days, participants were characterized as expected users, overusers, or underusers. Good controller medication adherence was defined as 80 percent or more of prescribed doses. Data also included demographic characteristics, spirometry, and scores from standardized questionnaires. Bivariate associations were examined to examine predictors of medication use.
Of the 416 participants, 51 percent were expected users, 27 percent were overusers, and 22 percent were underusers of albuterol. No differences were observed among the user groups by demographic characteristics or lung function. Expected users had the highest asthma-related knowledge, attitudes, and efficacy while overusers reported the greatest symptom burden, worst asthma control, and highest frequency of symptom days. Overusers also had the highest burden of depression symptoms with twice as many overusers being at risk of clinically relevant depression than expected users, 32 percent versus 17 percent, respectively. More frequent symptom days accounted for 15 percent of albuterol overuse and greater use on those symptom days accounted for another 31 percent. However, the majority of overuse, 54 percent, was attributable to greater use on symptom free days. Mean controller adherence was high across all albuterol user groups, and there were no differences between the groups. Among the 10 percent of participants who had <80 percent controller adherence, they too had higher risk of depression than adherent participants, 41 percent versus 20 percent, respectively.
“Even though overusers experienced more frequent symptom days and used more albuterol on those days, most overuse was attributable to unexpected use on symptom-free days,” said lead author Dr. Joe Gerald, assistant professor at Arizona. “Furthermore, depression appeared to be a common link between albuterol overuse and controller non-adherence.”
Additional research is needed to determine the role of depression on medication behaviors and whether treatment of depression might improve both depression and asthma control.