What is the recommended prn (as needed) dose of propranolol?

PRN Propranolol Dosing for Situational Anxiety

For situational or performance anxiety with prominent physical symptoms (tremor, palpitations, sweating), give propranolol 10-40 mg orally 30-60 minutes before the anxiety-provoking event, with a maximum single dose of 40 mg. 1

Patient Selection for PRN Use

PRN propranolol is most appropriate for:

• Patients with performance anxiety or specific situational triggers rather than generalized anxiety disorder 1
• Those experiencing predominantly somatic/physical symptoms of autonomic hyperactivity (tremor, palpitations, tachycardia, sweating) rather than psychological symptoms 1

Mandatory Pre-Treatment Screening

Before prescribing any propranolol, you must exclude absolute contraindications:

• Second or third-degree heart block 1, 2
• Decompensated heart failure or significant left ventricular dysfunction 1, 2
• Asthma or obstructive airway disease 1, 2
• Cardiogenic shock 1, 2
• Sinus node dysfunction without a pacemaker 1, 2
• Recent or ongoing hypoglycemic episodes 1

Perform baseline assessment including:

• Heart rate and blood pressure measurement 1, 2
• Cardiovascular examination with auscultation 1, 2
• Screen for history of bronchospasm, diabetes, and concurrent medications affecting cardiac conduction 1, 2

Dosing Algorithm for PRN Use

Starting approach:

• Begin with 10-20 mg as a test dose to assess individual response and tolerability
• Take 30-60 minutes before the anticipated stressful event to allow adequate absorption
• Maximum single PRN dose is 40 mg 1

Dose adjustment:

• If 10-20 mg provides insufficient symptom control, increase to 30-40 mg for subsequent events
• Most patients respond adequately to 20-40 mg PRN 1

Critical Safety Warnings

Propranolol masks hypoglycemia symptoms in diabetic patients - counsel diabetics about this risk and consider alternative agents 1, 2

Never use PRN propranolol for chronic daily anxiety - it is not effective for generalized social anxiety disorder and should only be used situationally 1

Monitor for hypotension and bradycardia, especially if the patient takes the medication more frequently than anticipated 1

Common Pitfalls to Avoid

• Do not prescribe propranolol for patients with predominantly psychological anxiety symptoms (worry, rumination) as they are unlikely to benefit 1
• Avoid combining with non-dihydropyridine calcium channel blockers (diltiazem, verapamil) due to increased risk of bradycardia and heart block 1, 2
• Counsel patients to take with food to reduce hypoglycemia risk, though this is less critical with PRN dosing than chronic use 1
• Warn patients not to take if they have wheezing, significantly reduced oral intake, or active vomiting 1

When PRN Dosing is Inappropriate

PRN propranolol is not suitable for:

• Generalized anxiety disorder requiring chronic treatment 1
• Patients needing daily symptom control (use scheduled dosing instead)
• Panic disorder (other agents are preferred)