Bronchodilator effects of indacaterol and formoterol in patients with COPD

Abstract

Background: Resting inspiratory capacity (IC) reflects static hyperinflation in chronic obstructive pulmonary disease (COPD). This study compared the effects of formoterol and indacaterol, a novel once-daily ultra-long-acting beta(2)-agonist (or ultra-LABA), on resting IC and forced expiratory volume in 1 s (FEV(1)).

Methods: Thirty patients with COPD (mean FEV(1)/FVC 0.49, mean FEV(1) 56% predicted) each inhaled three treatments (two in randomized sequence followed by open-label formoterol) on separate study days: a single dose of indacaterol 300 microg, matching placebo, and two doses of formoterol 12 microg 12 h apart.

Results: Indacaterol and formoterol increased FEV(1) and IC at all time points relative to placebo (p<0.001). Peak effects on FEV(1) were similar, while indacaterol had a greater effect on peak IC (31% vs 23% from pre-dose; p=0.034). Indacaterol had a greater effect than formoterol on FEV(1) at 8 h (1.47 vs 1.39 L; p=0.014) and 24 h (1.44 vs 1.35 L; p=0.003), and on IC from 4 to 24 h (differences of 0.13-0.19 L; p<0.05). At 24 h, indacaterol and formoterol increased FEV(1) by 17.7% and 7.5%, respectively, from pre-dose.

Conclusions: This study discriminated between the effects on IC and FEV(1) of once daily indacaterol and twice daily formoterol. The greater effect of indacaterol on IC may translate into improved long-term clinical outcomes.