In this study, the addition of tiotropium bromide to an inhaled glucocorticoid was evaluated as compared with doubling the dose of the inhaled glucocorticoid (primary superiority comparison) or the addition of salmeterol (secondary non-inferiority comparison) in 210 patients with asthma.

Tiotropium use showed a superior primary outcome, as compared with doubling of the inhaled glucocorticoid dose, as assessed by measuring the morning peak expiratory flow rate (PEF), with a mean difference of 25.8 l/min, and superiority in most secondary outcomes, including evening PEF, with a difference of 35.3 l/min, the proportion of asthma-control days, the FEV₁ before bronchodilation and daily symptom scores. The addition of tiotropium was also non-inferior to the addition of salmeterol for all assessed outcomes and increased the prebronchodilator FEV₁ more than salmeterol.

The study showed that tiotropium, when added to an inhaled glucocorticoid, improved symptoms and lung function in patients with inadequately controlled asthma. Its effects appeared to be equivalent to those with the addition of salmeterol. Additional studies that have sufficient statistical power to evaluate exacerbations and safety events are required to further establish the clinical efficacy of tiotropium in asthma.

▶ Peters SP, Kunselman SJ, Icitovic N, et al, for the National Heart, Lung, and Blood Institute, Asthma Clinical Research Network. Tiotropium bromide step-up therapy for adults with uncontrolled asthma. N Engl J Med 2010;363:1715–26.