A 58-year-old man with hypertension and chronic obstructive pulmonary disease (COPD) is being considered for beta-blocker therapy. All of the following statements regarding beta-blocker use in this patient are true EXCEPT:

Explanation

## Beta-Blockers in COPD: Safety and Selectivity ### The Clinical Dilemma **Key Point:** Beta-blockers can precipitate bronchospasm in COPD patients because β2-receptor blockade removes the bronchodilatory effect of endogenous catecholamines. The choice of agent is critical. ### Selectivity and COPD Safety | Agent Type | Mechanism of Concern | COPD Safety | |------------|----------------------|-------------| | Non-selective (propranolol, nadolol) | Block both β1 and β2 → unopposed α-mediated bronchoconstriction | **Contraindicated** | | β1-selective at therapeutic doses | Spare β2 → preserve bronchodilation | **Preferred** | | β1-selective at HIGH doses | Lose selectivity → block β2 → bronchospasm risk | **Caution required** | | Carvedilol (non-selective + α1 block) | Non-selective β-blockade + α1 antagonism | **Problematic in COPD** | **High-Yield:** Carvedilol is a **non-selective beta-blocker**, not a β1-selective agent. Its α1-blocking activity causes vasodilation but does NOT protect the airways. The non-selective β-blockade still blocks β2 receptors on bronchial smooth muscle, risking bronchospasm in COPD. ### Why Each Statement Is True (Except One) 1. **Non-selective beta-blockers are contraindicated in COPD** — TRUE. Propranolol, nadolol, and labetalol all block β2 receptors and increase bronchospasm risk. 2. **β1-selectivity is dose-dependent** — TRUE. At therapeutic doses, agents like atenolol and metoprolol are selective; at high doses, selectivity is lost and β2 blockade occurs. 3. **Carvedilol is safe in COPD because of α1 blockade** — **FALSE.** Carvedilol is non-selective for β-receptors. Its α1-antagonism causes vasodilation but does NOT prevent β2 blockade on airways. It is contraindicated in COPD. 4. **Atenolol is better than propranolol in COPD** — TRUE. Atenolol is β1-selective and safer; propranolol is non-selective and contraindicated. **Clinical Pearl:** In COPD patients requiring beta-blockade, use β1-selective agents (atenolol, metoprolol, bisoprolol) at standard therapeutic doses. Avoid non-selective agents and high-dose selective agents.