What is the typical dosing of propranolol (beta-blocker) for managing panic attacks?

Propranolol Dosing for Panic Attacks

For panic attacks, propranolol should be dosed at 40-80 mg orally every 6-8 hours as needed, with a typical starting dose of 10-20 mg taken 30-60 minutes before anticipated anxiety-provoking situations. This dosing regimen targets the peripheral manifestations of anxiety while minimizing side effects.

Dosing Algorithm for Propranolol in Panic Attacks

Initial Dosing

• Starting dose: 10-20 mg taken 30-60 minutes before anticipated anxiety-provoking situations
• Maintenance dose: 40-80 mg orally every 6-8 hours as needed
• Maximum daily dose: 160-320 mg divided into multiple doses

Dosing Considerations

• Lower doses (10-40 mg) are typically effective for situational anxiety and performance anxiety
• Higher doses (80-160 mg daily) may be required for recurrent panic attacks
• Divided dosing (3-4 times daily) provides more consistent beta-blockade

Mechanism and Efficacy

Propranolol works primarily by blocking peripheral beta-adrenergic receptors, reducing the somatic symptoms of anxiety such as tremor, tachycardia, and palpitations 1. It is most effective when somatic symptoms are prominent but not extreme in degree.

The efficacy of propranolol is best established for:

• Situational anxiety (e.g., performance anxiety)
• Somatic manifestations of panic (e.g., palpitations, tremor)
• As an adjunct to other anti-anxiety medications

Important Clinical Considerations

Monitoring Parameters

• Heart rate (target: not below 50-60 beats per minute)
• Blood pressure (avoid systolic BP < 90 mmHg)
• Signs of bronchospasm or wheezing
• Symptoms of hypoglycemia

Contraindications

• Marked first-degree AV block (PR interval > 0.24 seconds)
• Second or third-degree AV block without a functioning pacemaker
• History of asthma or reactive airway disease
• Severe left ventricular dysfunction or heart failure
• Hypotension (systolic BP < 90 mmHg)
• Significant bradycardia (heart rate < 50 beats per minute)

Cautions and Special Populations

• For patients with mild wheezing or history of COPD, start with a reduced dose (12.5 mg) of a cardioselective agent 2
• Use cautiously in patients with diabetes due to risk of masking hypoglycemia symptoms
• Avoid in patients with concurrent depression, as beta-blockers may worsen depressive symptoms 3

Combination Therapy

Some evidence suggests that combining propranolol with benzodiazepines like alprazolam may allow for lower doses of each medication while maintaining efficacy 4. This approach may be particularly useful for patients with both somatic and psychological symptoms of panic.

Clinical Pearls

• Propranolol begins working within 1-2 hours of administration 1
• It primarily addresses the physical symptoms of anxiety rather than the psychological aspects
• Propranolol is not FDA-approved specifically for panic disorder but is commonly used off-label
• Unlike benzodiazepines, propranolol does not carry a risk of dependence
• Abrupt discontinuation after prolonged use should be avoided to prevent rebound symptoms

Remember that propranolol primarily addresses the peripheral manifestations of anxiety and may need to be combined with other treatments that target the psychological aspects of panic disorder for optimal management.