Abstract
Effects of tiotropium, an inhaled long acting anti-cholinergic agent, on lung function were investigated in current smokers and non-smokers with asthma treated with inhaled glucocorticoids (ICS) plus long acting β2-agonists.
We conducted a double-blind, placebo-controlled, cross-over study of inhaled single dose of tiotropium in 10 asthmatics current smoking and 10 asthmatics who have never smoked. Lung function was measured before and 1, 3 and 24 hours after inhalation of 18 μg of tiotropium or placebo by HandiHaler®. The primary outcome was a change in forced expiratory volume in 1 second (FEV1) from baseline, and the secondary outcomes were changes in peak expiratory flow rate (PEFR), V50 and V25.
At baseline, asthmatics with and without smoking history had a mean FEV1 that was 2,590ml and 2,220ml, and were taking a mean dose of ICS of 1,208 and 1,000 μg/day, respectively. The increase from baseline FEV1 was 169ml and 105ml higher at 3 hours after tiotropium than after placebo in current smokers and non-smokers, respectively. PEFR, V50 and V25 were also significantly increased after tiotropium compared with placebo in both study groups. Changes in FEV1 and PEFR tended to be greater in asthmatics current smoking compared with subjects who have never smoked, although there were no statistical differences at any time points.
These findings suggest that tiotropium will provide a new strategy on treatment of bronchial asthma.
- Copyright ©ERS 2015
