Which drug class should a patient with a history of asthma not receive?

• A. ACE inhibitors
• B. Diuretics
• C. Beta blockers
• D. Calcium channel blockers

Answer: (C)

Beta-blockers should be avoided in asthma because they block beta-2 receptors in the bronchial smooth muscle. When beta-2 receptors are blocked, the airways can constrict more easily, leading to bronchospasm and wheezing in someone with asthma. This makes breathing harder during an asthma flare or even at baseline if the block is significant. That’s why, in patients with a history of asthma, nonselective beta-blockers (which block both beta-1 in the heart and beta-2 in the lungs) are avoided.

If a beta blocker is ever considered, a beta-1 selective (cardioselective) agent might be used at the lowest effective dose with close monitoring, but many clinicians still avoid it in uncontrolled asthma due to potential risk.

The other classes listed—ACE inhibitors, diuretics, and calcium channel blockers—do not carry the same risk of bronchoconstriction and are generally appropriate options for patients with asthma, though they have their own separate indications and side effects (ACE inhibitors can cause cough, diuretics affect fluid/electrolytes, calcium channel blockers have other cardiovascular effects).