Is it safe to reduce propranolol (beta blocker) from 20 mg three times a day (tid) to 10 mg every morning and afternoon and 20 mg at bedtime for an adult patient with a psychiatric history, experiencing dizziness while being treated for akathisia?

Propranolol Dose Reduction for Akathisia with Dizziness

Yes, reducing propranolol from 20 mg three times daily (60 mg total) to 10 mg morning and afternoon plus 20 mg at bedtime (40 mg total) is a reasonable and safe approach for managing dizziness while maintaining akathisia control.

Rationale for Dose Adjustment

The proposed reduction maintains a total daily dose of 40 mg, which remains within the therapeutic range for akathisia treatment. Propranolol doses of 30-80 mg/day have demonstrated substantial improvement in neuroleptic-induced akathisia, with most patients responding to these relatively low doses 1. Your patient's current 60 mg daily dose exceeds the minimum effective range, providing room for downward titration.

Evidence Supporting Lower Doses

• Complete remission of akathisia occurred in 9 of 14 patients using propranolol 30-80 mg/day, with response typically occurring within 24 hours 1
• Propranolol 20-30 mg/day was found dramatically effective in reducing neuroleptic-induced akathisia in controlled trials 2
• Even doses as low as 10 mg twice daily have shown efficacy, with gradual titration up to 40 mg four times daily as needed 3

Addressing the Dizziness

Dizziness is a well-documented adverse effect of propranolol, listed prominently in FDA labeling and multiple cardiovascular guidelines 4, 5. The symptom likely reflects:

• Hypotension from beta-blockade reducing cardiac output and blood pressure 6, 5
• Bradycardia contributing to reduced cerebral perfusion 4, 5
• Orthostatic effects, particularly if the patient has volume depletion or takes concurrent medications 6

Critical Safety Monitoring

Before implementing the dose reduction:

• Measure baseline heart rate and blood pressure, both supine and standing, to assess for orthostatic hypotension 7
• Check for bradycardia (heart rate <60 bpm) which may require more aggressive dose reduction 4
• Screen for concurrent medications that may potentiate hypotension, particularly ACE inhibitors, diuretics, or other antihypertensives 6
• Assess for volume depletion from diuretic therapy or inadequate fluid intake 6

Implementation Strategy

The proposed dosing schedule (10 mg morning, 10 mg afternoon, 20 mg bedtime) offers several advantages:

• Maintains coverage throughout the day for akathisia control
• Reduces peak plasma levels that may contribute to dizziness, as propranolol immediate-release has a half-life of only 3-6 hours 7
• Provides higher evening dose when akathisia symptoms may be more bothersome and dizziness less problematic during sleep
• Allows for further titration if needed

Tapering Considerations

Never abruptly discontinue propranolol, as this can precipitate rebound hypertension, tachycardia, or worsening of underlying conditions 7, 5. Your proposed reduction from 60 mg to 40 mg daily represents a 33% decrease, which is:

• Gradual enough to avoid withdrawal phenomena 5
• Sufficient to potentially alleviate dizziness while maintaining therapeutic effect 1, 2
• Easily reversible if akathisia symptoms worsen

Monitoring After Dose Reduction

Reassess the patient within 1-2 weeks to evaluate:

• Resolution or improvement of dizziness symptoms 7
• Maintenance of akathisia control, as response to propranolol typically occurs within 24 hours 1
• Heart rate and blood pressure to ensure adequate cardiovascular parameters 7
• Any new symptoms suggesting inadequate akathisia control (inner restlessness, urge to move, motor restlessness) 8

If Dizziness Persists at Lower Dose

• Consider switching to a beta-1 selective agent like metoprolol, which causes fewer peripheral vascular effects 9
• Evaluate for other causes of dizziness unrelated to propranolol
• Ensure adequate hydration and avoid rapid position changes 6

If Akathisia Worsens at Lower Dose

• Return to 20 mg three times daily and address dizziness through alternative strategies:
  • Optimize timing of doses relative to meals and activities
  • Ensure adequate hydration
  • Consider adding low-dose mirtazapine (7.5-15 mg once daily) as adjunctive therapy, which has compelling evidence for akathisia treatment 10
  • Evaluate for benzodiazepine augmentation if subjective distress persists despite beta-blocker therapy 8

Important Contraindications and Precautions

Ensure the patient does not have absolute contraindications to continued propranolol use:

• Asthma or obstructive airway disease (propranolol is non-selective and can cause bronchospasm) 4, 7, 5
• Second or third-degree heart block 7, 5
• Decompensated heart failure 4, 7, 5
• Severe bradycardia or sinus node dysfunction without pacemaker 7

In diabetic patients, propranolol may mask symptoms of hypoglycemia (tachycardia, tremor), making hypoglycemic episodes more difficult to recognize 5.