Esther H Zhou, Sally Seymour, Margie R Goulding, Elizabeth M Kang, Jacqueline M Major, Solomon Iyasu

Emerging safety issues associated with long-acting beta2-agonist (LABA) have led to multiple regulatory activities by the US Food and Drug Administration (FDA) since 2003, including Drug Safety Communications (DSCs) in 2010. These DSCs had three specific recommendations for the safe use of LABA products in adult asthma treatment. We examined the initiation of LABA-containing products for adult asthma treatment using an intermittent time series approach in a claims database from 2003 to 2012. We assessed the alignment of dispensing patterns with the following 2010 FDA recommendations: 1) contraindicated use of single-ingredient (SI)-LABA without an asthma controller medication (ACM); 2) a LABA should only be used when asthma is not adequately controlled on inhaled corticosteroids (ICSs) or ACM; and 3) step-down asthma therapy (e.g., discontinue LABA) when asthma control is achieved. There were 477,922 adults (18-64 years old) dispensed a new LABA during 2003-2012. Among LABA initiators, patients who initiated an SI-LABA and who did "not" have an ACM dispensed on the same date decreased from >9% in 2003 (the initial labeling change) to <2% post 2010 DSCs (p-value <0.0001 in the segmented regression model). The proportion of asthma patients dispensed an ICS in 6 months prior to initiating LABA treatment did not increase. The proportion of patients with longer than 4 months of continuous treatment did not decrease over the study period. Although the decrease in SI-LABA initiation is consistent with FDA's recommendations, low ICS dispensing before initiating a LABA and LABA continuation practices require further efforts to move toward the recommended safe practices.