Zafirlukast improves asthma symptoms and quality of life in patients with moderate reversible airflow obstruction

Background: Previous trials demonstrated the effectiveness of the leukotriene receptor antagonist zafirlukast in patients with mild-to-moderate asthma. Objectives: We sought to assess the efficacy and safety of zafirlukast and its effect on patients' quality of life (QOL) during a 13-week, double-blind, placebo-controlled, multicenter trial in adults and adolescents with moderate reversible airflow obstruction. Methods: Patients (age range, 12 to 68 years) with total daytime asthma symptoms scores of 10 or greater over 7 consecutive days (maximum, 21/wk), FEV1 45% or greater but less than or equal to 80% of predicted value (greater than or equal to 6 hours after beta(2)-agonist), and reversible airway disease were randomized to 20 mg zafirlukast twice daily (n(Z) = 231) or placebo twice daily (n(P) = 223). Efficacy was assessed from changes in daytime and nocturnal symptoms, beta(2)-agonist use, nasal congestion score, and pulmonary function. QOL was evaluated with a disease-specific Asthma Quality of Life Questionnaire. Safety was determined from adverse event information and clinical laboratory test results. Results: Zafirlukast was significantly (P < .001) more effective than placebo, with reductions from baseline in the daytime asthma symptoms score (-23%), nighttime awakenings with asthma (-19%), and beta(2)-agonist use (-24%) and improvements from baseline in morning (+25 L/min) and evening (+18 L/min) peak expiratory flow rates. Compared with placebo, zafirlukast significantly (P less than or equal to .018) improved scores for QOL domains (activity limitations, symptoms, emotional function, and exposure to environmental stimuli) and overall QOL, with a significantly greater proportion of zafirlukast-treated patients demonstrating clinically meaningful improvements (greater than or equal to 0.5-unit change from baseline; P less than or equal to .037). The safety profile of zafirlukast was clinically indistinguishable from that of placebo. Conclusions: Zafirlukast is effective and well tolerated and improves QOL in the long-term treatment of patients with moderate reversible airflow obstruction.