[Comparison of tiotropium inhalation capsules and ipratropium metered dose inhaler in a randomized, double-blind, double-dummy, efficacy and safety study in patients with chronic obstructive pulmonary disease].

OBJECTIVE:To compare the efficacy and safety between tiotropium capsule and ipratropium MDI in a 4 week treatment in patients with chronic obstructive pulmonary disease (COPD). METHODS:A multi-center, randomized, double blind, double dummy and parallel comparison clinical trial was conducted in 221 stable moderate to severe patients with COPD. They were randomized into tiotropium 18 microg once per day arm or ipratropium 2 puffs qid. arm for four weeks. The spirometry was conducted at 5 minutes pre-medication; and 30, 60, 120, and 180 minutes post-medication before; 2 weeks and 4 weeks after treatment. RESULTS:The forced expiratory volume in one second (FEV(1)) trough response, the primary endpoint, was significantly higher in the tiotropium arm than that of the ipratropium with (0.063 +/- 0.024) L (95% CI 0.016 - 0.111 L, t = 2.63, P = 0.009) after 4 weeks of treatment. Meanwhile the clinical evidences indicated the continuous improvement of bronchodilation in the tiotropium arm. Forced vital capacity (FVC) trough response was also significantly higher in the tiotropium arm 4 weeks after treatment with (0.133 +/- 0.047) L (t = 2.83, P = 0.005). By comparison with baseline, no significant differences were found between these two arms in the average change of FEV(1) as well as FVC 0 - 3 hours after inhalation (all P > 0.05). There was no significant difference in rescue medication consumptions (t = 0.60, P = 0.548). Adverse events occurred in 12 (10.9%) patients in the tiotropium arm and 18 (16.2%) in the ipratropium arm, without statistical difference (chi(2) = 1.326, P = 0.249). The major adverse event in the tiotropium group was dry mouth (5, 4.5%). No cardiac disorder or abnormal electrocardiogram was reported. CONCLUSION:The results indicated that tiotropium 18 microg once per day is more potent than ipratropium qid. in bronchodilation to COPD patients with the similar tolerance of ipratropium.