What are the uses and dosages of propranolol (beta-blocker)?

Propranolol: Clinical Uses and Dosing

Propranolol is a non-selective beta-blocker with FDA-approved indications for hypertension, angina pectoris, migraine prophylaxis, hypertrophic subaortic stenosis, and cardiac arrhythmias, with additional evidence-based uses in post-myocardial infarction, anxiety disorders, essential tremor, hyperthyroidism, portal hypertension, and ventricular arrhythmias. 1, 2

Cardiovascular Indications

Hypertension

• Initial dose: 80 mg once daily (extended-release formulation), titrated to 120-160 mg once daily for maintenance 1
• Maximum dose may reach 640 mg daily in resistant cases 1
• For immediate-release formulations in acute settings: 0.5-1 mg IV over 1 minute, repeated up to total dose of 0.1 mg/kg 3
• Full blood pressure response may take several days to weeks 1

Angina Pectoris

• Starting dose: 80 mg once daily (extended-release), gradually increased at 3-7 day intervals 1
• Optimal dose: 160 mg once daily on average, with maximum studied dose of 320 mg daily 1
• Evidence supports variable dosing up to 500-800 mg daily for optimal anti-anginal effect in moderate-to-severe cases 4
• Gradual discontinuation over several weeks is mandatory to prevent rebound angina 1, 5

Cardiac Arrhythmias

• Narrow-complex tachycardias (SVT, atrial fibrillation/flutter): 0.5-1 mg IV over 1 minute, repeated up to total 0.1 mg/kg 3
• Ventricular arrhythmias: Oral dosing 200-640 mg daily achieves suppression in 40% of patients beyond those responding to lower doses 6
• Plasma levels of 12-1100 ng/mL (end of dosing interval) produce 70-100% arrhythmia suppression 6
• Critical caveat: Avoid in pre-excited atrial fibrillation/flutter, decompensated heart failure, and asthma 3

Post-Myocardial Infarction

• Timing: Initiated 5-21 days post-MI 3
• Dosing: 180-240 mg daily (divided dosing with immediate-release) 3
• Reduces all-cause mortality with pooled relative risk of 0.87 (95% CI 0.80-0.95) 3

Hypertrophic Subaortic Stenosis

• Usual dose: 80-160 mg once daily (extended-release) 1

Neurological Indications

Migraine Prophylaxis

Adults:

• Initial dose: 80 mg once daily (extended-release) 1
• Effective range: 160-240 mg once daily 1
• Discontinue if no response after 4-6 weeks at maximum dose 1

Pediatric (American Academy of Pediatrics recommendations):

• Starting dose: 1 mg/kg/day divided into three doses 7
• Target maintenance: 2-3 mg/kg/day (maximum 3 mg/kg/day) 7
• Administration: With food to prevent hypoglycemia, divided into three daily doses 7
• Monitoring: Heart rate and blood pressure before initiation and at follow-ups 7
• Special populations: 0.5 mg/kg/day for children with hypoglycemia risk 7
• Hold during illness or reduced oral intake 7

Essential Tremor and Anxiety Disorders

• Performance anxiety: 10-40 mg as needed 30-60 minutes before event 2
• Chronic anxiety with physical symptoms: Start 30-60 mg daily, titrate based on response 5
• Most effective for tremor, palpitations, tachycardia, and sweating 5
• Mandatory pre-treatment assessment: Heart rate, blood pressure, cardiovascular examination, screening for bronchospasm history 5

Other Indications

Hyperthyroidism

• Controls sympathetic overactivity symptoms (tachycardia, tremor, anxiety) 2, 8
• Typical dosing: 40-160 mg daily in divided doses 8

Portal Hypertension

• Reduces risk of upper gastrointestinal bleeding 2, 8

Pheochromocytoma

• Used only after alpha-blockade is established 8

Critical Safety Considerations

Absolute Contraindications

• Sinus bradycardia, second or third-degree heart block 3, 5
• Decompensated heart failure 3, 5
• Asthma or reactive airway disease (risk of bronchospasm) 3, 7, 5
• Cardiogenic shock 5
• Active hypoglycemic episodes 5

Monitoring Requirements

• Before initiation: Heart rate, blood pressure, cardiovascular examination 7, 5
• During treatment: Monitor for hypotension, bradycardia (especially during dose escalation) 3, 5
• Pediatric patients: More frequent monitoring, especially under 8 weeks of age 7

Common Adverse Effects

• Fatigue, bradycardia, hypotension, dizziness, cold extremities 5
• Masks hypoglycemia symptoms in diabetic patients 5
• Potential worsening of heart failure 5

Discontinuation Protocol

• Never discontinue abruptly after chronic use—risk of rebound hypertension, tachycardia, or angina 5, 1
• Taper gradually over several weeks, adjusting for patient age, comorbidities, and dose 1, 5

Formulation Considerations

• Extended-release formulations provide 8-11 hour half-life with once-daily dosing 9
• Bioavailability of extended-release is 30-50% less than immediate-release due to increased first-pass metabolism 9
• Not mg-for-mg equivalent: Switching from immediate to extended-release requires retitration 1
• Peak concentrations are lower and delayed with extended-release, but maintain therapeutic effect throughout 24 hours 9