What is the appropriate dosage and treatment regimen for beta blockers, such as metoprolol, in patients experiencing chest palpitations?

Beta Blockers for Chest Palpitations: Dosage and Treatment Regimen

Metoprolol is the preferred beta blocker for chest palpitations, with an initial oral dose of 25-50mg twice daily, gradually titrated to a maximum of 100mg twice daily based on heart rate response, targeting 50-60 beats per minute. 1, 2

Initial Selection and Dosing

Intravenous Administration (Acute Setting)

• For acute management of palpitations requiring immediate intervention:
  • Administer metoprolol 5mg IV over 1-2 minutes
  • May repeat 5mg every 5 minutes up to a total dose of 15mg
  • Monitor vital signs, ECG, and symptoms continuously during administration 2, 1

Oral Administration (Outpatient Setting)

• Initial dosing:

  • Metoprolol tartrate: 25-50mg twice daily 2, 1
  • Metoprolol succinate (extended-release): 25-50mg once daily 1
  • Bisoprolol: 1.25mg once daily 2
  • Carvedilol: 3.125mg twice daily 2

• Titration schedule:

  • Increase dose at 2-week intervals 2
  • Double the dose if heart rate remains above target and patient tolerates current dose
  • Target heart rate: 50-60 beats per minute 2

• Maximum doses:

  • Metoprolol tartrate: 100mg twice daily (200mg/day) 2
  • Metoprolol succinate: 200mg once daily 2, 1
  • Bisoprolol: 10mg once daily 2
  • Carvedilol: 25-50mg twice daily 2

Beta Blocker Selection

Preferred Agents

1. Metoprolol (first-line for most patients)

   • Cardioselective (beta-1 selective)
   • Available in immediate-release (twice daily) and extended-release (once daily) formulations
   • Effective for rate control and maintaining sinus rhythm 3

2. Bisoprolol

   • Highly cardioselective
   • Once-daily dosing
   • Good option for patients with mild respiratory disease 2

3. Carvedilol

   • Combined alpha and beta blockade
   • Particularly beneficial in patients with concomitant heart failure 2

Monitoring and Follow-up

• Initial follow-up: 2 weeks after starting therapy
• Parameters to monitor:
  • Heart rate (target 50-60 beats per minute)
  • Blood pressure
  • Symptom improvement
  • Side effects
• ECG monitoring: At baseline and with significant dose changes
• Laboratory monitoring: Check blood chemistry 12 weeks after initiation and 12 weeks after final dose titration 2

Special Considerations

Contraindications

• Marked first-degree AV block (PR interval >0.24 sec)
• Second or third-degree AV block without pacemaker
• Severe bradycardia (heart rate <50 beats per minute)
• Hypotension (systolic BP <90 mmHg)
• Decompensated heart failure
• Cardiogenic shock
• Severe bronchospastic disease 2

Cautions

• Mild to moderate COPD or asthma: Use cardioselective agents (metoprolol, bisoprolol) at lower doses
• For mild wheezing: Consider reduced dose (12.5mg metoprolol) rather than avoiding beta blockers 2
• Diabetes: Monitor glucose levels more frequently
• Elderly patients: Start with lower doses (12.5-25mg metoprolol)
• Renal impairment: No dose adjustment needed for metoprolol 4
• Hepatic impairment: Use lower doses with cautious titration 4

Management of Side Effects

• Fatigue or dizziness: Consider reducing dose by 50%
• Bradycardia (HR <50): Reduce dose by 50% or discontinue if severe
• Bronchospasm: Switch to more cardioselective agent or discontinue
• Worsening heart failure: Double diuretic dose and/or halve beta blocker dose 2

Patient Education

• Explain that benefits may develop slowly (3-6 months)
• Temporary symptom worsening may occur during initiation (20-30% of cases)
• Advise against abrupt discontinuation (can worsen palpitations)
• Instruct to report significant side effects but not to stop medication without consulting physician
• Recommend daily weight monitoring; increase diuretic if weight increases by 1.5-2.0 kg over 2 days 2

Beta blockers are highly effective for managing chest palpitations, with metoprolol being the most commonly used agent due to its cardioselectivity and favorable side effect profile. Starting with low doses and gradually titrating while monitoring heart rate provides the optimal balance of efficacy and tolerability.