A long-term evaluation of once-daily inhaled tiotropium in chronic obstructive pulmonary disease (COPD) shows that tiotropium is an effective once-daily bronchodilator that reduces dyspnea and the frequency of COPD exacerbations, and improves health status. The study involved 921 patients with stable COPD, enrolled in two identical randomized double-blind placebo-controlled trials over 12 months. Patients received either tiotropium (18 μg) or placebo once daily. Tiotropium provided significantly better bronchodilation compared to placebo, with a 12% improvement in trough FEV1 and a 22% improvement in mean response during the 3 hours following dosing. Tiotropium recipients experienced less dyspnea, better health status scores, and fewer exacerbations and hospitalizations. Adverse events were comparable between groups, except for dry mouth, which was more common in the tiotropium group. Tiotropium's long duration of action (24 hours) allows for once-daily dosing and sustained bronchodilation over 12 months. The study confirms that tiotropium is a safe and effective treatment for COPD, with significant improvements in symptoms, health status, and exacerbation frequency. The results suggest that tiotropium will make an important contribution to COPD therapy.A long-term evaluation of once-daily inhaled tiotropium in chronic obstructive pulmonary disease (COPD) shows that tiotropium is an effective once-daily bronchodilator that reduces dyspnea and the frequency of COPD exacerbations, and improves health status. The study involved 921 patients with stable COPD, enrolled in two identical randomized double-blind placebo-controlled trials over 12 months. Patients received either tiotropium (18 μg) or placebo once daily. Tiotropium provided significantly better bronchodilation compared to placebo, with a 12% improvement in trough FEV1 and a 22% improvement in mean response during the 3 hours following dosing. Tiotropium recipients experienced less dyspnea, better health status scores, and fewer exacerbations and hospitalizations. Adverse events were comparable between groups, except for dry mouth, which was more common in the tiotropium group. Tiotropium's long duration of action (24 hours) allows for once-daily dosing and sustained bronchodilation over 12 months. The study confirms that tiotropium is a safe and effective treatment for COPD, with significant improvements in symptoms, health status, and exacerbation frequency. The results suggest that tiotropium will make an important contribution to COPD therapy.