22 In studies in adults, montelukast, 10 mg once daily, compared with placebo, demonstrated significant improvements in morning FEV1 (10.4% vs 2.7% change from baseline), AM peak expiratory flow rate (PEFR) (24.5 L/ min vs 3.3 L/ min change from baseline), and significant decrease in total β -agonist use (-26.1% vs -4.6% change from baseline).