β2-agonists

β2-adrenergic receptors are located on the airway smooth muscle of large and small airways, as well as on mast cells and post-capillary venules.7 Adrenaline activates β2-adrenergic receptors and leads to smooth muscle relaxation. Thus, the action of β2-agonists, which selectively activate β2-adrenergic receptors, directly causes bronchodilation.35 Two types of β2-agonist are used in the treatment of COPD:

  • Short-acting β2-agonists (SABAs; e.g., salbutamol [or albuterol, the US Adopted Name]) are effective for up to 12 hours, and are usually used by patients ‘on demand’ as rescue medication to relieve symptoms.1
  • Long-acting β2-agonists (LABAs; e.g. salmeterol, formoterol, indacaterol, arformoterol, and olodaterol) are effective for 12–24 hours, and are used as maintenance therapy, and depending on the agent, are recommended to be used once or twice daily.1
    • Salmeterol
      • Salmeterol (metered dose: 25 µg; delivered dose: 21 µg) is administered twice daily and has a 12-hour duration of action.1,36
      • Twice-daily treatment with salmeterol significantly improves lung function (measured by FEV1) compared with placebo.37,38
      • Treatment with salmeterol significantly improved dyspnoea,37,38 exercise capacity,37,39 HRQoL (measured by SGRQ)38 and exacerbations,40 compared with placebo.
      • Salmeterol is generally well tolerated.39
    • Formoterol
      • Formoterol (metered and delivered dose: 12 µg) is administered twice daily and has a 12-hour duration of action; it is indicated for the relief of reversible airways obstruction in COPD patients.1,41
      • Twice-daily treatment with formoterol significantly improves lung function compared with placebo.39,42
      • Treatment with formoterol significantly improves dyspnoea (measured by TDI), exercise capacity and HRQoL (measured by SGRQ), compared with placebo.39,42
      • Formoterol is generally well tolerated.39
    • Indacaterol
      • Indacaterol (metered dose: 150 or 300 µg; delivered dose: 120 or 240 µg) has a 24-hour duration of action, and is therefore suitable for once-daily dosing.1,43
      • Indacaterol is indicated for maintenance bronchodilator treatment of airflow obstruction in adult patients WITH copd.43
      • Once-daily treatment with indacaterol significantly improves lung function (trough FEV1) compared with placebo.38,44
      • Treatment with indacaterol significantly improves dyspnoea (measured by TDI), health status (measured by SGRQ), exercise endurance and exacerbations, compared with placebo.38,45,46
      • Once-daily treatment with indacaterol also significantly improves dyspnoea and health status compared with tiotropium.44,47
      • Indacaterol is generally well tolerated.46
    • Arformoterol
      • Arformoterol (metered dose: 15 µg) is administered twice daily and has a 12-hour duration of action; it is indicated for the maintenance treatment of bronchoconstriction in COPD patients.1,48
      • Twice-daily treatment with arformoterol significantly improves lung function (measured by trough FEV1 and FEV1 AUC0-12) compared with placebo.49,50
      • Treatment with arformoterol significantly improves dyspnoea (measured by TDI) and health status (measured by SGRQ) and reduces exacerbation-related hospitalisations, compared with placebo.49,50,51
      • Arformoterol is generally well tolerated.50
    • Olodaterol
      • Olodaterol (2.5 µg per puff) is administered once daily to a total dose of 5 µg (two puffs) and is indicated as a maintenance bronchodilator treatment in COPD patients.1,52
      • Treatment with olodaterol improved lung function compared with placebo over 48 weeks of treatment.53
      • Treatment with olodaterol has also been shown to improve dyspnoea, health status (SGRQ total score) and exercise tolerance compared with placebo.53
      • Olodaterol is generally well tolerated and has an acceptable cardiovascular event profile.53