Beta-blocker
Formal Definition
Beta-adrenergic receptor antagonists: a drug class (e.g., metoprolol, carvedilol, atenolol) that competitively blocks catecholamine binding at beta-1 (cardiac) and/or beta-2 (pulmonary, vascular) receptors, reducing heart rate, contractility, and blood pressure; cornerstone of HFrEF, post-MI, and rate-control therapy.
How It's Used on the Ward
"Beta-blocked" or "on a beta-blocker" — essential vocabulary; "do NOT abruptly stop beta-blockers" is a cardinal ward rule.
Example
""Patient came in for hip surgery and someone held all home meds including metoprolol 100 mg twice daily. Post-op day 1: HR 138, hypertensive, diaphoretic. Abrupt beta-blocker withdrawal. Restarting immediately.""
Clinical Context
Cardioselective (beta-1): metoprolol, atenolol, bisoprolol — safer in COPD/asthma patients. Non-selective: carvedilol (alpha + beta) — preferred in HFrEF. Never abruptly stop in patients on chronic therapy: rebound tachycardia, hypertension, angina, arrhythmia. Acute decompensated HF: hold beta-blocker if the patient is "cold and wet" — but do NOT stop in the patient who is stable on it. Contraindications: decompensated HF, reactive airway disease (relative), high-degree AV block, severe bradycardia.