Short Term Effects of Tiotropium on COPD Patients Treated with Long Acting Bronchodilators

BACKGROUND: The results of bronchodilator therapy in chronic obstructive pulmonary disease (COPD) are not satisfactory and because of this, many drugs are administered for treatment of disease. We examined the short-term additive bronchodilator effects of tiotropium in patients with stable COPD already treated with salmeterol twice daily. MATERIALS AND METHODS: In a double-blind, double-dummy randomized study we evaluated the acute bronchodilator efficacy of a single 18 µg dose of tiotropium in patients with COPD under chronic treatment with a long acting beta-adrenergic (salmeterol 50µg twice a day). Measurements of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and six-minute walking test (6 MWT) as indicator of daily activities were made before and after giving the drug. A total of 129 outpatients with stable COPD (Gold level 2 -3- 4) were enrolled and 92 completed the study. RESULTS: Tiotropium elicited a significantly greater bronchodilation than the placebo. The action of the drug was elicited as increase in FEV1 (p ≤ 0.001) and FVC (p ≤ 0.001); 6-MWT increased 35 meters in patients treated with tiotropium compared to 2.5 meters in those receiving placebo (p ≤ 0.001). CONCLUSION: Addition of tiotropium to chronic administration of a beta-adrenergic drug such as salmeterol induced an increase in pulmonary function parameters and in exercise capacity suggesting that association of the two drugs can be more efficient for treatment of disease and improvement of daily living activities than beta-adrenergics alone.