PHARMACOLOGY Indacaterol is a long-acting partial β2-adrenoceptor agonist with a rapid onset of action. It stimulates intracellular adenyl cyclase, resulting in increased levels of cyclic adenosine monophosphate. This causes relaxation of bronchial smooth muscle; therefore, indacaterol acts locally as a bronchodilator when inhaled.1 CLINICAL STUDIES The safety and efficacy of indacaterol 150 microgram once daily was assessed in a 12-week, double-blind study in 416 patients with moderate to severe COPD. Patients were randomised to receive either indacaterol or placebo once daily. Indacaterol had a bronchodilator efficacy superior to that of placebo, as indicated by higher 24-hour post-dose FEV1 values at week 12 (p<0.001) and after the first dose (p<0.001). The overall rate of adverse events was comparable between the two groups. The most common adverse events were worsening of COPD (incidence of 8.5% in the indacaterol group and 12.2% in the placebo group), and cough (6.2% and 7.3%, respectively).2 In another double-blind study, 1,732 patients with moderate to severe COPD were randomised to receive indacaterol 300 or 600 microgram once daily, formoterol 12 microgram twice daily, or placebo. Investigators measured the trough FEV1 at week 12 and assessed health-related quality of life (HRQOL) using the St George’s Respiratory Questionnaire (SGRQ) at baseline and weeks 4, 8, 12, 24, 44 and 52. Trough FEV1 (adjusted for baseline lung function, smoking status and country) at week 12 was 1.48L for indacaterol, 1.38L for formoterol and 1.31L for placebo (p<0.001 for both agents vs placebo). Differences in trough FEV1 for both doses of indacaterol against placebo exceeded those for formoterol versus placebo after 1 day (140ml and 170ml vs 110ml), at week 12 (170ml and 170ml vs 70ml) and at week 52 (160ml and 150ml vs 50ml).3 Compared with patients who received placebo, the SGRQ total score was significantly lower at each assessment in those who received indacaterol (p<0.001 for both doses) or formoterol (p<0.01). Differences versus placebo in adjusted mean total score were similar to or exceeded the minimum clinically important difference from week 8 with indacaterol and from week 52 with formoterol.4 The overall incidence of adverse events over ?52 weeks was similar for the active treatments ?and placebo.5 A 26-week randomised, double-blind study compared the effects of indacaterol (150 microgram or 300 microgram once daily), tiotropium (18 microgram once daily; open-label) and placebo in 1,683 patients with moderate to severe COPD. FEV1 was measured at week 12 and HRQOL was evaluated using the SGRQ at baseline and weeks 4, 8, 12 and 26. At week 12, the increases in trough FEV1 compared to placebo were 180ml for both doses of indacaterol and 140ml for tiotropium (p<0.001 for all comparisons vs placebo). Indacaterol gave better SGRQ total scores than placebo at each assessment (150 microgram, p≤0.001; 300 microgram, p<0.01). The differences between tiotropium and placebo were not significant. Adverse events occurred at similar rates in the 4 groups.6 研究证实：诺华公司新上市的支气管扩张剂“茚达特罗”Indacatero治疗支气管哮喘24小时有效。 Indacatero是诺华公司新上市的支气管扩张剂。是第一个新型的吸入型复合制剂，用于每日1次治疗成人患者慢性阻塞性肺疾病（COPD）。Indacatero是第一个也是唯一的能够吸入后5分钟内起效，并能保证24小时支气管扩张的药物。 为了研究indacaterol治疗支气管哮喘的疗效。研究人员对42例支气管哮喘患者进行了一项双盲交换研究，评估indacaterol的安全性及疗效。 纳入的42例患者随机通过压力定量气雾剂加压水化氟代烷接受单次剂量indacaterol(50,100,200和400μg)或安慰剂。在给药后30分钟和21小时通过评估一秒钟用力呼气量比较indacaterol和安慰剂初期治疗的有效性。 结果显示，各种剂量都会延长支气管扩张。从安慰剂对照组到200和400μg的indacaterol，一秒钟用力呼气量在给药后30分钟平均分别增加了7.6％和14.9％，在给药后21小时分别增加了7.5％和10.4％。在这些剂量下，相对于安慰剂的一秒钟用力呼气量改变从5分钟到25小时显著改变。在5分钟，对于indacaterol200和400μg剂量的一秒钟用力呼气量的几何最小二乘值为3.08和3.22L，而安慰剂的为2.99L。 在给药后第24小时，indacaterol50,100,200和400μg剂量的一秒钟用力呼气量的基线－校正几何最小二乘值分别为3.13,3.11,3.24和3.30L，而安慰剂的为2.98L，所有的治疗均可接受。而每日一次剂量200和400μg的indacaterol可使得支气管扩张维持24小时，且快速起效并有好的耐受性和安全性。 研究结果表明，新型的吸入型β2受体兴奋剂Indacaterol能在哮喘中使得支气管扩张持续24小时。此研究结果再次证实了Indacaterol起效快，作用时间长等优点，疗效显著。每日一次用药更方便安全。