A patient with COPD is prescribed a medication to help reduce bronchospasm by blocking muscarinic receptors in the airways, leading to bronchodilation. Which medication should the nurse anticipate administering?

Ipratropium is an anticholinergic (antimuscarinic) bronchodilator that works by blocking muscarinic receptors in the airway smooth muscle. This blockade inhibits bronchoconstriction and reduces mucus secretion, resulting in bronchodilation. It is commonly used in the management of COPD, either alone or in combination with short-acting beta-2 agonists, and directly matches the mechanism described in the stem. Montelukast is a leukotriene receptor antagonist more commonly used in asthma management; it works by blocking inflammatory mediators rather than muscarinic receptors and is not a first-line agent for COPD bronchospasm. Theophylline is a methylxanthine that causes bronchodilation through phosphodiesterase inhibition, increasing cyclic AMP, but it does not act on muscarinic receptors. Fluticasone is an inhaled corticosteroid that reduces airway inflammation but has no direct bronchodilatory effect via muscarinic receptor blockade. The specific mechanism described — blocking muscarinic receptors to produce bronchodilation — uniquely and precisely identifies ipratropium as the correct answer, distinguishing it from the other options that act through entirely different pathways.