A randomized controlled trial to assess the efficacy of tiotropium in Canadian patients with chronic obstructive pulmonary disease.
BACKGROUND
Patients with chronic obstructive pulmonary disease (COPD) who smoke have a greater annual rate of decline in forced expiratory volume in 1 s (FEV(1)) than those patients who have stopped smoking.


OBJECTIVE
To assess the effect of tiotropium on pre-dose (trough) FEV(1) in patients with COPD followed in Canada.


METHODS
A total of 913 patients were randomly assigned to receive either tiotropium 18 mug once daily (n=608) or placebo (usual care minus inhaled anticholinergics) (n=305) for 48 weeks in the present randomized, double-blind, parallel-group study. The effect of tiotropium on measurements of lung function (FEV(1), FEV(6) and forced vital capacity), symptoms, health-related quality of life (St George's Respiratory Questionnaire) and exacerbations were examined.


RESULTS
Tiotropium improved trough FEV(1) in both current and ex-smokers compared with placebo. Baseline FEV(1) in smokers and ex-smokers was 1.03 L and 0.93 L, respectively (P<0.001). At week 48, the mean difference between the tiotropium and placebo groups was 0.14+/-0.04 L (P<0.001) in the smoker group and 0.08+/-0.02 L (P<0.0001) in the ex-smoker group. Tiotropium also significantly improved trough forced vital capacity and FEV(6) compared with placebo throughout the treatment period (P<0.05, for all). Furthermore, tiotropium significantly improved the St George's Respiratory Questionnaire total score compared with placebo at week 48 (40.9 versus 43.7 units, P<0.005).


CONCLUSIONS
Compared with the placebo group, tiotropium provides sustained improvements in lung function in patients with COPD, with improvements for smokers and ex-smokers.
University Health Network, Toronto General Hospital, Toronto, Canada. charles.chan@uhn.on.ca
Charles K N
CK
Chan
François
F
Maltais
Chris
C
Sigouin
Jennifer M
JM
Haddon
Gordon T
GT
Ford
D000368:Aged; D002170:Canada; D018678:Cholinergic Agents / Q000494:pharmacology*; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D011788:Quality of Life; D012602:Scopolamine Derivatives / Q000494:pharmacology*; D012648:Self Care; D012907:Smoking / Q000009:adverse effects*; D013147:Spirometry; D000069447:Tiotropium Bromide
D018678:Cholinergic Agents; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide