Beta-Blockers
Medications blocking beta-adrenergic receptors for cardiac conditions
Definition
Beta-blockers are a class of medications that block beta-adrenergic receptors, slowing heart rate, reducing myocardial contractility, and lowering blood pressure. They are used for hypertension, heart failure, angina, arrhythmias, MI, and migraine prevention.
Common Drugs (ends in '-olol')
- Selective beta-1 (cardioselective): Metoprolol, atenolol, bisoprolol, nebivolol. Safer in asthma/COPD.
- Non-selective (beta-1 and beta-2): Propranolol, nadolol. Caution in reactive airway disease.
- Alpha and beta: Labetalol, carvedilol. Used in hypertensive crisis and heart failure.
Side Effects
- Bradycardia
- Hypotension
- Fatigue, dizziness
- Bronchospasm (especially non-selective)
- Masking hypoglycemia symptoms in diabetics
- Cold extremities
- Sexual dysfunction
Contraindications
Severe bradycardia, heart block (2nd and 3rd degree without pacemaker), cardiogenic shock, severe asthma.
Nursing Considerations
- Check apical pulse and BP before each dose. Hold for HR less than 60 or SBP less than 90.
- Do NOT discontinue abruptly (rebound hypertension, tachycardia, MI).
- Teach patients to rise slowly (orthostatic hypotension).
- Monitor diabetic patients closely; beta-blockers mask hypoglycemia symptoms except diaphoresis.
NCLEX Relevance
Hold parameters and do-not-stop-abruptly teaching are high-yield. Know beta-1 vs non-selective differences.