Tiotropium: an inhaled, long-acting anticholinergic drug for chronic obstructive pulmonary disease.

Inhaled anticholinergic drugs are considered one of the principal bronchodilator treatments for chronic obstructive pulmonary disease (COPD). Ipratropium bromide is an anticholinergic drug frequently administered for the treatment of COPD. Unfortunately, ipratropium has a short duration of action, requiring administration every 6 hours; this regimen affects adherence to drug therapy. Tiotropium bromide is structurally similar to ipratropium and is under development in the United States. The duration of action of tiotropium is approximately 24 hours, allowing for once-daily dosing. Other than xerostomia being more common with tiotropium than with ipratropium, the safety profiles of these drugs were similar in studied populations. On the basis of its improvements in trough spirometric measurements and improved pharmacokinetic profile compared with that of ipratropium, tiotropium is likely to become the first-line anticholinergic agent in the treatment of patients with COPD.