Two, once daily (q.d.) inhaled bronchodilators are available for the treatment of chronic obstructive pulmonary disease (COPD): the β2-agonist indacaterol and the anticholinergic tiotropium. This blinded study compared the efficacy of these two agents and assessed their safety and tolerability.

Patients with moderate-to-severe COPD were randomised to treatment with indacaterol 150 μg q.d. (n=797) or tiotropium 18 μg q.d. (n=801) for 12 weeks.

After 12 weeks, the two treatments had similar overall effects on “trough” (24 h post-dose) forced expiratory volume in 1 s. Indacaterol-treated patients had greater improvements in transition dyspnoea index (TDI) total score (least squares means 2.01 versus 1.43; p<0.001) and St George’s Respiratory Questionnaire (SGRQ) total score (least squares means 37.1 versus 39.2; p<0.001; raw mean change from baseline -5.1 versus -3.0), and were significantly more likely to achieve clinically relevant improvements in these end-points (indacaterol versus tiotropium odds ratios of 1.49 for TDI and 1.43 for SGRQ, both p<0.001). Adverse events were recorded for 39.7% and 37.2% of patients in the indacaterol and tiotropium treatment groups, respectively. The most frequent adverse events were COPD worsening, cough and nasopharyngitis.

Both bronchodilators demonstrated spirometric efficacy. The two treatments were well tolerated with similar adverse event profiles. Compared with tiotropium, indacaterol provided significantly greater improvements in clinical outcomes.


  • Received December 13, 2010.
  • Accepted April 24, 2011.
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