Propranolol: Non-Selective Beta-Blocker
Propranolol is a non-selective beta-adrenergic receptor blocker (beta-1 and beta-2) with a wide range of indications including hypertension, angina, arrhythmias, heart failure (low-dose), essential tremor, migraine prophylaxis, anxiety (situational), and hyperthyroidism.
One of the oldest beta-blockers, propranolol is highly lipophilic, crosses the blood-brain barrier (CNS effects), and has no intrinsic sympathomimetic activity. Available in oral and intravenous formulations.
Mechanism of Action
Competitive antagonism at beta-1 and beta-2 adrenergic receptors. Beta-1 blockade reduces heart rate, contractility, and cardiac output. Beta-2 blockade causes bronchoconstriction (limiting use in asthma/COPD) and inhibits glycogenolysis. High lipophilicity enables CNS penetration for tremor and anxiety indications.
Indications & Use
Hypertension, angina pectoris, cardiac arrhythmias (AF rate control, SVT), essential tremor, migraine prophylaxis, situational anxiety (stage fright), thyrotoxicosis (symptom control), hypertrophic obstructive cardiomyopathy, portal hypertension.
Dosage
Hypertension: 40–80 mg twice daily or 80–160 mg once daily (modified-release). Migraine: 80–160 mg/day in divided doses. Tremor: 40 mg twice daily. Titrate gradually; avoid abrupt withdrawal (rebound hypertension/angina).
Side Effects
Common: fatigue, cold extremities, bradycardia, sexual dysfunction, nightmares (high CNS penetration). Bronchospasm (beta-2 blockade). Masking of hypoglycaemia symptoms in diabetics.
Drug Interactions
Verapamil/diltiazem: severe bradycardia and AV block — avoid IV combination. NSAIDs: reduce antihypertensive effect. Antidiabetics: masks hypoglycaemia signs. CYP2D6 inhibitors: increase propranolol levels.
Contraindications
Asthma/reactive airway disease, uncompensated heart failure, severe bradycardia, AV block (2nd/3rd degree), cardiogenic shock, pheochromocytoma (without alpha-blocker cover).
Frequently Asked Questions
Can I take propranolol for anxiety?
Yes — propranolol is widely used for situational anxiety (public speaking, examinations, performance anxiety). It reduces the peripheral symptoms (tremor, palpitations, sweating) but does not affect cognition or sedation.
Why should I not stop propranolol suddenly?
Abrupt withdrawal can cause rebound tachycardia, hypertension, and in patients with coronary artery disease, precipitate unstable angina or myocardial infarction. Always taper over 1–2 weeks.
Why can propranolol not be used in asthma?
Beta-2 receptor blockade in the bronchi causes bronchoconstriction, which can trigger life-threatening bronchospasm in asthma patients. Cardioselective beta-blockers (metoprolol, bisoprolol) are safer but still used cautiously in severe asthma.
References
- ESC Arrhythmia Guidelines
- Propranolol in essential tremor — Cochrane Review
- EMA product information propranolol
Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice.