Background: Tiotropium bromide is a new inhaled anticholinergic agent approved for once-daily, long-term maintenance treatment of bronchospasm associated with chronic obstructive pulmonary disease (COPD).
Objective: This article reviews the pharmacology, pharmacokinetic and pharmacodynamic properties, clinical efficacy, tolerability, and cost of tiotropium therapy in patients with COPD.
Methods: The MEDLINE (1966-October 2004), Iowa Drug Information Service (1966-October 2004), and International Pharmaceutical Abstracts (1970-November 2004) databases were searched for original research and review articles published in English. The search terms were tiotropium, Ba 679 BR, and HandiHaler. Reference lists from these articles were also consulted, as was selected information provided by the manufacturer of tiotropium. All relevant identified studies were included in the review, with preference given to Phase II/III trials. Pharmacoeconomic studies were limited to those conducted in the United States.
Results: Tiotropium is a nonselective anticholinergic agent that exhibits kinetic receptor selectivity for the muscarinic M1 and M3 receptors. After inhalation, tiotropium has an onset of action within 30 minutes, a peak effect within 3 to 4 hours, and a > or = 24-hour duration of action that allows once-daily dosing. In clinical trials, patients receiving tiotropium 18 microg QD had significant improvements in trough, peak, and mean forced expiratory volume in 1 second (FEV1), dyspnea, and health-related quality of life, as well as fewer COPD exacerbations and hospitalizations, compared with patients receiving placebo and ipratropium (all, P < 0.05). Improvement in FEV1 was also significantly greater in patients who received tiotropium compared with those who received salmeterol (P < 0.05), although the number of exacerbations and extent of health resource use were comparable between groups. Dry mouth was the most commonly reported adverse effect. One analysis found tiotropium to be cost-effective compared with ipratropium.
Conclusions: Tiotropium offers several advantages over ipratropium in the management of COPD. Long-term (> 1 year) studies are necessary to determine the impact of tiotropium on disease progression and life expectancy.