Which medication class is contraindicated in asthma and may cause impotence?

• A. ACE inhibitors
• B. Spironolactone
• C. Beta-blockers
• D. Hydralazine

Answer: (C)

The key idea is how certain heart medications affect airways and blood flow. Beta-blockers block beta-adrenergic receptors. In the lungs, beta-2 receptors normally promote bronchodilation; blocking them can cause bronchoconstriction, which worsens asthma. Because of this, beta-blockers are generally avoided in asthma or used only with great caution, especially nonselective ones that block both beta-1 and beta-2 receptors.

They can also cause impotence because they diminish sympathetic signals that assist penile blood flow and vascular responses needed for an erection. This side effect is more commonly seen with older, nonselective agents, though some patients on cardioselective beta-1 blockers may experience it as well.

So the medication class that fits both parts of the question—contraindicated in asthma and associated with erectile dysfunction—is beta-blockers.