The management of chronic obstructive pulmonary disease (COPD) has changed dramatically over the past few years. With the introduction of newer medications and alternative delivery systems for older medications, physicians have multiple options to provide symptom reduction and improved lung function. One of the new advances has been the development of anticholinergic therapy for COPD treatment. Because of the advantage of this class of medications, the current treatment guidelines for COPD patients recommend these agents as first-line therapy. One of the newer agents is tiotropium. This medication with anticholinergic properties provides once-daily dosing and sustained bron-chodilation. Salmeterol, a long-acting beta ₂ agonist, has also been reported to be effective in the treatment of COPD. Donohue and associates compared the effectiveness and safety of tiotropium and salmeterol in the treatment of patients with COPD.

The trial was a six-month, randomized, placebo-controlled, double-blind, double-dummy, parallel-group study. Patients who met the inclusion criteria were randomized to receive tiotropium in a dosage of 18 mcg once daily via dry-powder inhaler, salmeterol in a dosage of 50 mcg twice daily via metered-dose inhaler, or placebo. Outcome measures included frequent lung function measurements, and evaluation of dyspnea and health-related quality of life. Adverse events were monitored during the study.

There were 623 patients enrolled in the study from multiple centers in 12 countries. The treatment and placebo groups were similar with regard to age, gender, and baseline lung function. At six months, the tiotropium group showed a better improvement in lung function, better dyspnea scores, and better scores on the quality-of-life instrument than the salmeterol group. Both inhaled medications reduced the need for rescue albuterol when compared with placebo. The most common side effect of tiotropium was dry mouth (10 percent), but none of the patients discontinued the treatment because of this side effect. There were no treatment-associated laboratory or electrocardiographic abnormalities.

The authors conclude that tiotropium used once daily produced superior bronchodilation and reduced dyspnea in patients with COPD when compared with salmeterol. Patients treated with tiotropium also indicated more improvement in their health-related quality-of-life questionnaire than those treated with salmeterol. Because of these advantages, tiotropium should be considered first-line treatment in patients with COPD.