The use of long-acting β2- agonists as monotherapy in children and adults.

BACKGROUND In asthma, it is recommended that long-acting β2-agonists (LABAs) not be used as monotherapy, but, be used with inhaled corticosteroids (ICS) to minimize the risk of serious adverse events. OBJECTIVE To test the hypothesis that if clinical recommendations were followed, LABA monotherapy would not occur in children and would only occur in COPD, where it is not contraindicated. METHODS We analyzed LABA and ICS dispensing for British Columbians with respiratory conditions in 2004. LABA use was classified as "LABA Monotherapy", "LABA with Concurrent ICS", or "Mixed" (LABA use, occasional ICS use). Using physician and hospital billing records, children < 18 years were classified as having "asthma" or "other respiratory condition". Adults were classified as having "asthma", "COPD", "asthma and COPD", or "other respiratory condition". We calculated the prevalence of LABA monotherapy, and the association between LABA monotherapy and diagnosis, age, gender, and location of residence. RESULTS LABA monotherapy occurred in 3.4% (n=140) of pediatric and 3.9% (n=1837) of adult LABA users and in 3.4% of children with asthma and 3.0% of adults with asthma. In children, LABA monotherapy was associated with female gender (odds ratio (OR) 1.62; 95% confidence interval (CI) 1.14, 2.82; p<0.0065) and adolescence (age 12-18 years; 2.30; CI 1.53,3.46; p<0.0001). In adults, LABA monotherapy was associated with a COPD diagnosis, and being greater than 60 years old (p<0.0001). CONCLUSION LABA monotherapy occurs in children and adults. LABA monotherapy in children, especially in girls and adolescents, could expose them to serious adverse events and requires further study.