Tiotropium Benefits Some Patients Who Don't Respond to β-Agonists

Tiotropium (Spiriva), a long-acting antimuscarinic agent, is FDA approved as first-line therapy for patients with chronic obstructive pulmonary disease; however, as add-on therapy, it also benefits some patients with asthma that is not controlled by inhaled corticosteroids (ICS) alone. To evaluate predictors of response to tiotropium (compared with the long-acting β-agonist salmeterol [Serevent]), researchers analyzed data from a previous 14-week crossover trial in which double-dose ICS, ICS plus salmeterol, and ICS plus tiotropium were compared in 210 adult asthma patients.

Roughly equal numbers of patients responded to tiotropium and salmeterol. Some patients responded just to tiotropium (26%) or just to salmeterol (14%) but not both. Pati…