Tiotropium: A novel anticholinergic for the once-daily treatment of COPD (PDF)

Chronic obstructive pulmonary disease (COPD) is a major public health problem, with inhaled anticholinergic agents being the treatment of choice. The disadvantage of currently approved therapies for the treatment of COPD is that agents such as ipratropium (Atrovent, Boehringer Ingelheim) must be administered numerous times daily. Tiotropium (Spiriva, Pfizer/Boehringer Ingelheim) is a new, recently FDA-approved, long-acting anticholinergic drug that requires only once-daily dosing. Tiotropium displays selective receptor kinetics by dissociating more slowly from M1 and M3 receptors than M2 receptors. In patients with COPD, tiotropium 18 mcg inhaled once daily results in significant improvement in lung function. Furthermore, improvements appear sustained for up to 3 weeks after discontinuing tiotropium. Tiotropium is well tolerated with minimal systemic absorption resulting in a favorable adverse effect profile. The most common adverse effect associated with tiotropium is dry mouth. Given the longer duration of action, once-daily dosing, minimal adverse effects, and documented improvements in lung function, tiotropium is poised to replace ipratropium as the inhaled anticholinergic of choice.