2024-2025 © Uva Clinical Anaesthesia and Intensive Care ISSN 2827-7198 / Pharmacology / Propranolol 2024-2025 © Uva Clinical Anaesthesia and Intensive Care ISSN 2827-7198 / Pharmacology / Propranolol 2024-2025 © Uva Clinical Anaesthesia and Intensive Care ISSN 2827-7198 / Pharmacology / Propranolol 1 Propranolol: Mechanisms, Efficacy, and Safety Considerations Indunil Karunarathna 1 , Sanjeewa Dius 1 , R Ranwala 1 , Sau Bandara 1 , Sanjaya Godage 1 , PN Rodrigo 1 , Asoka Jayawardana 1 , U Vidanagama 1 , C Fernando 1 , U Ekanayake 1 , T Hapuarachchi 1 , P Gunasena 1 , P Aluthge 1 , N Perera 1 , S Gunathilake 1 , Kapila De Alvis 1 , K Gunawardana 1 , S Rajapaksha 1 , A Warnakulasooriya 1 , P Athulgama 1 , 1. Ministry of Health / Teaching Hospital Badulla / University of Colombo. 2024-2025 © Uva Clinical Anaesthesia and Intensive Care ISSN 2827-7198 / Pharmacology / Propranolol Abstract: Propranolol, a nonselective beta-adrenergic receptor antagonist, has revolutionized the treatment of cardiovascular and noncardiovascular conditions since its development by Sir James Black. This medication exerts its effects by competitively inhibiting beta-1 and beta-2 adrenergic receptors, reducing cardiac workload, heart rate, and oxygen demand. Widely used for heart failure, arrhythmias, hypertension, and migraine prophylaxis, propranolol is also utilized off-label for conditions such as performance anxiety and infantile hemangiomas. However, its nonselective action raises concerns in certain populations, such as patients with asthma or diabetes. This review examines propranolol's pharmacodynamics, administration, contraindications, adverse effects, and clinical applications. By exploring its diverse therapeutic roles, this article highlights the critical importance of an interprofessional approach to maximize benefits and minimize risks in propranolol therapy. Keywords: Propranolol, beta-blocker, cardiovascular therapy, indications, contraindications, mechanism of action, adverse effects, clinical applications Key Points Pharmacology: Propranolol is a nonselective beta- blocker with effects on both beta-1 and beta-2 adrenergic receptors. Cardiovascular Indications: Includes heart failure, atrial fibrillation, angina, hypertension, and post-myocardial infarction management. Noncardiovascular Indications: Prophylaxis of migraines, treatment of essential tremor, infantile hemangiomas, and performance anxiety. Contraindications: Asthma, COPD, bradycardia, diabetes with risk of hypoglycemia masking, and cocaine toxicity. Toxicity and Management: Overdose requires glucagon therapy and supportive measures. Interprofessional Collaboration: Effective use of propranolol depends on coordinated care and patient education. Introduction Propranolol, introduced in the 1960s, marked a significant milestone in pharmacotherapy as the first beta-adrenergic receptor antagonist. Its discovery earned Sir James Black the Nobel Prize and led to widespread adoption of beta- blockers in clinical practice. Propranolol’s nonselective beta-blocking properties make it a cornerstone for managing cardiovascular conditions, including hypertension, atrial fibrillation, and angina. Beyond cardiovascular indications, propranolol's effects on the sympathetic nervous system have enabled its use in noncardiovascular diseases, such as migraine prophylaxis, essential tremor, and certain psychiatric conditions like performance anxiety. Despite its extensive benefits, propranolol’s broad receptor activity necessitates caution. Nonselective beta- blockade can exacerbate respiratory conditions such as asthma and may mask hypoglycemia symptoms in