The patency of small airways is assessed by the forced expiratory flow (FEF25–75%), which is decreased in obstructive airways due to mucus secretion, bronchospasm, inflammation, and alveolar destruction. The purpose of this analysis was to determine the effect of fluticasone propionate 250 mcg/salmeterol 50 mcg therapy (FSC 250/50) compared to ipratropium 36mcg/ albuterol 206mcg (Ipr/Alb) on the small airways in patients with COPD.
In this multicenter, double-blind, double-dummy study, 361 patients with COPD were randomized to FSC 250/50 BID via the Diskus or Ipr/Alb QID via a metered-dose inhaler for 8 weeks. The function of the small airways was investigated by measurement of the FEF25–75% at baseline and at 1, 4 and 8 weeks of therapy. Patients had COPD, an extensive smoking history (mean = 59 pack years) and impaired lung function (mean FEV1 43% of predicted).
Pre-dose FEF25–75% mL/sec Mean Δ from Baseline (SE)FSC 250/50 (n = 179)Ipr/Alb (n = 181)p-valueWeek 144.5 (13.4)−9.7 (9.5)<0.001Week 443.4 (12.9)−3.7 (12.5)0.007Week 855.0 (16.7)−6.6 (11.7)<0.001Endpoint56.9 (16.0)−6.8 (10.9)<0.001
In patients with COPD, FSC 250/50 caused significant improvements in small airway function within the first week and was sustained with continued therapy.
In patients with COPD treatment with FSC250/50 demonstrated improvements in small airway function, suggesting that the prolonged improvements in lung function may be due to the anti-inflammatory effects of the combination.
K. Knobil, Employee of GSK, Industry; support: GlaxoSmithKline