What is the recommended dosing for propranolol (beta blocker) in elderly patients with tremors?

Propranolol Dosing for Essential Tremor in the Elderly

Start propranolol at 40 mg twice daily (80 mg total daily dose) in elderly patients with tremor, titrating cautiously to a target of 120-160 mg daily in divided doses, with lower maximum doses and slower titration compared to younger patients due to age-related pharmacokinetic changes and increased risk of adverse effects. 1, 2

Initial Dosing Strategy

• Begin with 40 mg twice daily (80 mg total) rather than higher starting doses to minimize risk of hypotension, bradycardia, and other adverse effects that are more common in elderly patients 1, 2
• The American College of Cardiology recommends that elderly patients require lower doses due to altered pharmacokinetics 1
• Immediate-release formulations are preferred initially to allow for more flexible dose adjustments 1

Titration Protocol

• Increase by 40-80 mg daily every 1-2 weeks based on tremor response and tolerability, monitoring heart rate and blood pressure with each significant dose increase 2
• Target maintenance dose is typically 120-160 mg daily in 2-3 divided doses (e.g., 40 mg three times daily or 60 mg twice daily) 1, 2, 3
• Most therapeutic benefit occurs at plasma levels achieved by 120-240 mg daily, with optimal tremor reduction often seen at relatively low plasma propranolol concentrations (below 20-40 ng/ml) 3
• Maximum dose should generally not exceed 240 mg daily in elderly patients, compared to 640 mg in younger adults 1

Pre-Treatment Assessment Requirements

Before initiating propranolol, screen for absolute contraindications 1, 2:

• Second or third-degree heart block (check baseline ECG if cardiac history present)
• Decompensated heart failure (perform cardiovascular examination with auscultation)
• Asthma or obstructive airway disease (screen for history of bronchospasm)
• Sinus node dysfunction without pacemaker
• Cardiogenic shock or severe hypotension

Measure baseline heart rate and blood pressure before starting treatment 1, 2

Monitoring During Treatment

• Check heart rate and blood pressure at each dose escalation, holding doses if heart rate falls below 55 bpm or systolic BP below 90 mmHg 2
• Watch for dose-limiting adverse effects including 2, 4:
  • Bradycardia (most common)
  • Hypotension and dizziness
  • Fatigue or sleep disturbances
  • Cold extremities
  • Bronchospasm in susceptible individuals
• Chronic side effects occur in approximately 17% of patients on long-term propranolol therapy 4

Expected Response and Efficacy

• Approximately 70% of patients will experience meaningful tremor reduction, with improvement most pronounced in upper extremity tremor 5, 4
• Propranolol reduces tremor amplitude but does not affect tremor frequency 6
• Response may be better in patients with slower tremor frequencies (around 10 Hz) 6
• 30% of patients will have no therapeutic benefit and should have the medication discontinued after an adequate 3-month trial at 120 mg daily 4, 7

Age-Related Considerations

Elderly patients (≥60 years) have diminished response rates compared to younger patients 7:

• No patients over age 60 achieved "excellent" response in long-term studies 7
• Best responses occurred in patients under age 55, particularly those under 35 years 7
• Response tends to deteriorate over time if initial response is less than excellent 7
• Tolerance to therapeutic effect develops in approximately 12.5% of patients with chronic use 4

Critical Safety Warnings

• Never abruptly discontinue propranolol after chronic use, as this can precipitate rebound hypertension, tachycardia, or angina; taper gradually over several weeks when stopping 1, 2
• Propranolol may mask hypoglycemia symptoms in diabetic patients, requiring closer glucose monitoring 1
• Avoid combining with non-dihydropyridine calcium channel blockers (diltiazem, verapamil) due to increased risk of severe bradycardia and heart block 1
• Hold doses during periods of diminished oral intake or vomiting to reduce hypoglycemia risk 1

When to Discontinue or Switch Therapy

If no significant tremor improvement is observed after 3 months at 120 mg daily, decrease the dose and discontinue the medication, as further dose escalation is unlikely to provide benefit 7