Background: Salmeterol xinafoate is a long-acting, highly selective, beta2-adrenergic agonist that produces bronchodilation and clinically significant improvement in pulmonary function for up to 12 hours in patients with asthma.
Objective: To evaluate the impact on asthma-specific quality of life, efficacy, and safety of salmeterol versus albuterol in adult patients with mild-to-moderate persistent asthma.
Methods: A randomized, double-blind, double-dummy, parallel-group, multicenter study was conducted in 539 adult asthma patients over 12 weeks. Patients were randomized to receive either salmeterol 42 microg via metered-dose inhaler twice daily or albuterol 180 microg four times daily. Upon entry into the study, 46% of patients were being treated with an inhaled corticosteroid and were allowed to continue treatment throughout the study. Pulmonary function and asthma symptoms were monitored daily, and patients completed the Asthma Quality of Life Questionnaire (AQLQ) at baseline and after 4, 8, and 12 weeks of treatment.
Results: Treatment with salmeterol twice daily produced significantly greater improvements from baseline in all quality of life domain ("Activity Limitation," "Asthma Symptoms," "Emotional Function," "Environmental Exposure") scores and in the global AQLQ score at 12 weeks (P < or = .038) compared with albuterol treatment four times daily. Pulmonary function and asthma symptoms were also significantly improved with salmeterol compared with albuterol.
Conclusions: Salmeterol 42 microg administered twice daily is significantly more effective than albuterol 180 microg four times daily for improving asthma-specific quality of life, controlling asthma symptoms, and improving pulmonary function in patients with mild-to-moderate persistent asthma. Furthermore, those improvements were maintained over a 12-week period.