A 68-year-old man has COPD with moderate airway obstruction. Which agent is an appropriate addition to his current therapy of salmeterol?

The appropriate addition to the therapy of a 68-year-old man with moderate airway obstruction due to COPD who is currently on salmeterol is tiotropium. This choice is supported by the role of tiotropium as a long-acting anticholinergic bronchodilator, which works by blocking the action of acetylcholine on muscarinic receptors in the airways. This leads to smooth muscle relaxation and dilation of the airways, offering an additive effect to the already existing long-acting beta-agonist (salmeterol) therapy.

Using tiotropium in conjunction with salmeterol helps to improve lung function, reduce exacerbations, and enhance overall management of COPD symptoms. Its once-daily dosing is convenient and improves patient adherence to treatment. The combination therapy is particularly beneficial in individuals with more advanced stages of COPD or those who have persistent symptoms despite therapy with long-acting bronchodilators alone.

Other agents listed may have roles in COPD management, but they do not align with the most appropriate approach in this particular context. For example, systemic corticosteroids are typically reserved for acute exacerbations rather than for ongoing management. Albuterol, a short-acting beta-agonist, is generally used for quick relief rather