High long-term use of short-acting ß2-agonists indicates difficult-to-control adult-onset asthma
Published: April 7, 2022
Short-acting ß2-agonists (SABA) are effective bronchodilators that rapidly relieve asthmatic symptoms, such as shortness of breath, and therefore are used as-needed as relievers in asthma therapy. However, the symptoms of asthma caused by chronic inflammation of airways needs to be treated with anti-inflammatory medication, generally being maintenance therapy with inhaled corticosteroids (ICS). Recent short-term studies have associated high use of SABA with poor outcomes of asthma, but no studies existed on long-term SABA use in patients with clinically confirmed adult-onset asthma. In addition, studies on this topic have often lacked the information of disease control and patients’ adherence to controller treatment (such as ICS), both affecting the need for SABA. Vähätalo et al. were able to evaluate these factors in relation to long-term SABA use in their study published in The Journal of Allergy and Clinical Immunology: In Practice.
The current 12-year follow-up study included 203 patients with the diagnosis of new-onset adult asthma as part of the Seinäjoki Adult Asthma Study (SAAS). Asthma diagnosis was based on lung function measurements and typical symptoms of asthma and was confirmed by a respiratory specialist. Information on dispensed SABA and ICS during the follow-up was obtained from the Finnish Social Insurance Institution, which records all purchased medication from Finnish pharmacies. Patients’ use of SABA was quantified as canisters collected annually (per calendar year) and cumulatively over the 12-year period. High SABA use was defined as =36 SABA canisters in 12 years, corresponding to an average of =3 dispensed canisters per year. This was done to determine if patients with high SABA use and overreliance on SABA exist in this cohort of patients with adult-onset asthma and to analyze how these patients differ from those using less SABA. Patients’ 12-year adherence to ICS, asthma control, lung-function, and comorbidities were also assessed.
Based on the authors’ findings, only 10% of the study patients were classi?ed as high SABA users during the 12-year study period, and none of the patients were fully over-reliant on SABA i.e. not using ICS at all. Patients with high SABA use (=3 dispensed canisters/y) had more symptoms, higher number of emergency department visits, and more oral corticosteroid and antibiotic courses versus low SABA users (<3 dispensed SABA canisters/y). In addition, 86% of high SABA users had uncontrolled asthma, and over one quarter of the patients had severe asthma according to European Respiratory Society/American Thoracic Society criteria. Yet, high SABA users had better 12-year adherence to ICS treatment (98% vs 65%) as well as higher BMI (Body mass index), less education years, and more comorbidities compared to patients with low SABA use. Vähätalo et al. concluded that as high SABA use was associated with more severe asthma, these patients should be recognized in clinical practice. However, based on these results, rather than high use of SABA being dangerous as such, authors consider the high SABA use as a danger signal indicating more severe and/or uncontrolled asthma needing further therapeutic intervention.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.