What is the recommended dosage of propanolol (as needed) for anxiety?

Propranolol PRN Dosing for Anxiety

For as-needed (PRN) anxiety management, propranolol 10-40 mg taken 30-60 minutes before anxiety-provoking situations is the recommended approach, with 20 mg being the most commonly effective single dose for performance anxiety and situational stress. 1, 2, 3

Patient Selection

Propranolol works best for anxiety with prominent physical symptoms rather than purely psychological worry. 1, 4

Ideal candidates experience:

• Tremor, palpitations, tachycardia, and sweating 1, 3
• Performance anxiety (public speaking, test-taking, social situations) 2, 5
• Mild to moderate situational anxiety with somatic manifestations 4

Propranolol is less effective for patients with primarily psychic anxiety (racing thoughts, worry, psychological distress without physical symptoms). 4

Absolute Contraindications - Must Screen Before Prescribing

Never prescribe propranolol if the patient has: 1, 6

• Asthma or reactive airway disease (can cause life-threatening bronchospasm) 1
• Second or third-degree heart block 1, 6
• Decompensated heart failure 1, 6
• Cardiogenic shock 1, 6
• Severe hypotension 1
• Sinus node dysfunction without a pacemaker 1, 6

Recommended PRN Dosing Protocol

Start with 10-20 mg taken 30-60 minutes before the anticipated stressful event. 2, 7

Dose titration based on response:

• Initial dose: 10-20 mg for most patients 2, 7
• Standard effective dose: 20-40 mg for performance anxiety 2, 3, 7
• Maximum single PRN dose: 40 mg 2, 3
• Clinical effect occurs within 1-2 hours 3

A 20 mg dose provides significant anxiety reduction with minimal side effects compared to 40 mg, which carries higher risk of bradycardia (25%) and hypotension (10%). 7

Critical Safety Instructions for Patients

Instruct patients to check their pulse before each dose and hold if heart rate is below 60 bpm. 1

Additional safety counseling:

• Take with food to reduce hypoglycemia risk 8, 6
• Hold doses during illness with reduced oral intake or vomiting 8, 9
• In diabetic patients, propranolol masks hypoglycemia symptoms (tremor, tachycardia), making low blood sugar harder to recognize 1, 6

Pre-Treatment Assessment

Before prescribing, obtain: 6, 1

• Heart rate and blood pressure measurement 6
• History of asthma, bronchospasm, or reactive airway disease 6, 1
• History of heart block, heart failure, or cardiac conduction abnormalities 6, 1
• Diabetes status (increased monitoring needed) 1
• Current medications, especially calcium channel blockers 6

Routine ECG or echocardiogram is NOT required for healthy patients without cardiac symptoms. 6

Monitoring for PRN Use

No routine monitoring is required for occasional as-needed use in healthy patients. 6, 1

Patients should monitor for:

• Fatigue, dizziness, cold extremities 1, 6
• Bradycardia (pulse <60 bpm) 1
• Hypotension symptoms (lightheadedness) 6

Drug Interactions - Critical Pitfall

Never combine propranolol with non-dihydropyridine calcium channel blockers (diltiazem, verapamil) due to excessive bradycardia and heart block risk. 6, 1

Duration of Use

PRN propranolol is most appropriate for intermittent, predictable anxiety-provoking situations. 2, 3

• Effective for single-dose use before specific events 5, 7
• If anxiety occurs more than 2-3 times weekly, consider scheduled dosing (80-160 mg daily in divided doses) rather than PRN use 6, 3
• Evidence for efficacy beyond 4 weeks of continuous use is limited 2

Common Pitfall

Propranolol does NOT work for panic attacks or severe acute anxiety - the physical symptoms in these conditions are too extreme for beta-blockade alone. 3 It is most effective for mild to moderate somatic anxiety symptoms. 2, 3