Pinealitis accompanying equine recurrent uveitis.

Abstract

<b>Background:</b> In chronic obstructive pulmonary disease (COPD), the degree of circadian variation in forced expiratory volume in 1 second (FEV₁) and the influence of anticholinergic blockade is not known. Tiotropium is a long acting inhaled anticholinergic bronchodilator that increases daytime FEV₁ in COPD. We hypothesised that tiotropium would modify the overnight change in FEV₁, and this would be unaffected by the timing of drug administration. <b>Methods:</b> A double blind, randomised, placebo controlled trial was conducted with tiotropium 18 mg once daily in the morning (09.00 hours), evening (21.00 hours), or an identical placebo. Patients with stable COPD (n=121, FEV₁=41% predicted) underwent spirometric tests every 3 hours for 24 hours at baseline and after 6 weeks of treatment. <b>Results:</b> There were no significant differences at baseline between the groups. Tiotropium improved mean (SE) FEV₁ (over 24 hours) in the morning (1.11 (0.03) l) and evening (1.06 (0.03) l) groups compared with placebo (0.90 (0.03) l), and nocturnal FEV₁ (mean of 03.00 and 06.00 hours) in the morning (1.03 (0.03) l) and evening (1.04 (0.03) l) groups compared with placebo (0.82 (0.03) l) at the 6 week visit (p&lt;0.01). FEV₁ before morning or evening dosing was similar, while the peak FEV₁ moved later in the day with active treatment. The mean percentage change in FEV₁ from 09.00 hours to 03.00 hours (the nocturnal decline in FEV₁) was −2.8% in the morning group, −1.0% in the evening group, and −12.8% in the placebo group. The magnitude of the peak to trough change in FEV₁ was not statistically different. <b>Conclusions:</b> Tiotropium produced sustained bronchodilation throughout the 24 hour day without necessarily abolishing circadian variation in airway calibre.