Efficacy and safety of single therapeutic and supratherapeutic doses of indacaterol versus salmeterol and salbutamol in patients with asthma

ABSTRACT Objective: This study compared the bronchodilator efficacy and safety of indacaterol with placebo, salbutamol and salmeterol, in patients with persistent asthma, at single therapeutic and supratherapeutic doses. Research design and methods: This was a randomised, open-label crossover study in adult subjects with asthma (forced expiratory volume in 1 second [FEV1] ≥ 60% predicted). In part A, patients (n = 20) received single doses of indacaterol 200 µg, salbutamol 200 µg, salmeterol 50 µg and placebo. In part B, patients (n = 19) received single doses of indacaterol 1000 µg, salbutamol 1000 µg, salmeterol 250 µg and placebo. Main outcomes measures; Results: For the primary endpoint, FEV1 area under the effect curve during 0–24 h, indacaterol 200 µg was statistically superior to placebo and salbutamol. Indacaterol 200 µg FEV1 was higher than placebo (5 min to 24 h), salbutamol 200 µg (4–24 h), and salmeterol 50 µg (5 and 15 min and 22 and 24 h). Few adverse events were reported; all were mild or moderate in severity. Initial changes were observed in glucose, potassium, heart rate and QTc interval, but all values remained within normal ranges. Values matched placebo levels after a shorter time for indacaterol 1000 µg than for salmeterol 250 µg. Conclusions: In this single-dose, open-label study, indacaterol 200 µg provided effective 24‐h bronchodilation, with a longer duration than salmeterol 50 µg and a good overall safety profile. The sustained bronchodilation of indacaterol 1000 µg was not associated with sustained systemic adverse effects.