PT - JOURNAL ARTICLE AU - E. Naline AU - A. Trifilieff AU - R. A. Fairhurst AU - C. Advenier AU - M. Molimard TI - Effect of indacaterol, a novel long-acting β<sub>2</sub>-agonist, on isolated human bronchi AID - 10.1183/09031936.00032806 DP - 2007 Mar 01 TA - European Respiratory Journal PG - 575--581 VI - 29 IP - 3 4099 - http://erj.ersjournals.com/content/29/3/575.short 4100 - http://erj.ersjournals.com/content/29/3/575.full SO - Eur Respir J2007 Mar 01; 29 AB - Indacaterol is a novel β2-adrenoceptor agonist in development for the once-daily treatment of asthma and chronic obstructive pulmonary disease. The present study evaluated the relaxant effect of indacaterol on isolated human bronchi obtained from lungs of patients undergoing surgery for lung carcinoma. Potency (-logEC50), maximal relaxant effect (Emax) and onset of action were determined at resting tone. Duration of action was determined against cholinergic neural contraction induced by electrical field stimulation (EFS). At resting tone, -logEC50 and Emax values were 8.82±0.41 and 77±5% for indacaterol, 9.84±0.22 and 94±1% for formoterol, 8.36±0.16 and 74±4% for salmeterol, and 8.43±0.22 and 84±4% for salbutamol, respectively. In contrast to salmeterol, indacaterol did not antagonise the isoprenaline response. Indacaterol's onset of action (7.8±0.7 min) was not significantly different from that of formoterol (5.8±0.7 min) or salbutamol (11.0±4.0 min), but it was significantly faster than that of salmeterol (19.4±4.3 min). EFS-induced contractions were inhibited with -logIC50 values of 6.96±0.13 (indacaterol), 8.96±0.18 (formoterol), 7.18±0.34 (salmeterol) and 6.39±0.26 (salbutamol). Duration of action was &gt;12 h for indacaterol and salmeterol, and 35.3±8.8 and 14.6±3.7 min for formoterol and salbutamol, respectively. In isolated human bronchi, indacaterol behaved as a long-acting β2-adrenoceptor agonist with high intrinsic efficacy and fast onset of action.