The spirometric efficacy of once-daily dosing with tiotropium in stable COPD - A 13-week multicenter trial

Study objective: To compare the bronchodilator efficacy and safety of tiotropium and placebo. Design: A 3-month, randomized, double-blind, placebo-controlled, multicenter trial. Setting: Outpatient. Patients: Four hundred seventy patients with stable COPD (mean FEV1 = 38.6% predicted). Interventions: Tiotropium 18 mug (N = 279) or placebo (N = 191) given once daily via a lactose-based dry-powder inhaler device. Measurements and results: Spirometry was evaluated on days 1, 8, 50, and 92. Data were expressed as the mean trough (ie, before morning close; 23 to 24 h after previous dose) and average response observed in the 3 h after the dose was received. Tiotropium produced significant improvement in trough FEV1 and FVC, averaging 12% greater than baseline on day 8; these improvements were maintained on days 50 and 92. The average postdose FEV1 was 16% greater than baseline on day 1 and 20% greater than baseline on day 92; FVC was 17% greater than baseline oil day 1 and 19% greater than baseline on day 92, Tiotropium was significantly more effective than placebo in both trough and average FEV1 and FVC response (p < 0.001). These spirometric effects were corroborated by significant improvements in daily morning and evening peak expiratory flow rate, as well asa reduction in "as-needed" albuterol use. Symptoms of wheezing and shortness of breath were significantly less in patients receiving tiotropium, and the physician global assessment noted overall improvements with those treated with tiotropium relative to placebo. The most common reported adverse event after tiotropium was dry mouth (9.3% vs 1.6% relative to placebo; p < 0.05). Conclusions: These data demonstrate that tiotropium is a safe and effective once-daily anticho-linergic bronchodilator and should prove useful as first-line maintenance therapy in COPD.