What is the recommended dosage of Metoprolol (beta-blocker) for hypertension, angina, or heart failure?

Recommended Dosage of Metoprolol for Hypertension, Angina, and Heart Failure

For hypertension, angina, and heart failure, metoprolol should be initiated at a low dose and gradually titrated to target doses: metoprolol succinate 12.5-25 mg once daily initially, titrated to 200 mg once daily for heart failure and hypertension; or metoprolol tartrate 25-50 mg twice daily for angina and hypertension.

Metoprolol Formulations and Indications

Metoprolol is available in two primary formulations, each with specific dosing recommendations:

1. Metoprolol Succinate (Extended-Release):

   • Preferred for heart failure and hypertension
   • Once-daily dosing
   • Maintains more consistent blood levels

2. Metoprolol Tartrate (Immediate-Release):

   • Used for hypertension and angina
   • Typically twice-daily dosing
   • Also used in acute myocardial infarction settings

Dosing Recommendations by Condition

Heart Failure

• Initial dose: 12.5-25 mg metoprolol succinate once daily 1
• Target dose: 200 mg once daily 1, 2
• Titration: Double the dose every 2 weeks if tolerated 1
• Only use evidence-based beta-blockers (metoprolol succinate, carvedilol, or bisoprolol) as they have demonstrated mortality reduction 2

Hypertension

• Metoprolol Succinate:

  • Initial dose: 25-50 mg once daily 3
  • Effective range: 100-400 mg once daily 3
  • Titration: Adjust at 1-2 week intervals based on blood pressure response

• Metoprolol Tartrate:

  • Initial dose: 50 mg twice daily 3
  • Effective range: 100-450 mg daily in divided doses 3
  • Titration: Adjust at 1-week intervals based on blood pressure response

Angina Pectoris

• Metoprolol Tartrate:
  • Initial dose: 50 mg twice daily 3
  • Effective range: 100-400 mg daily in divided doses 3, 4
  • Titration: Adjust based on symptom control and exercise tolerance

Acute Myocardial Infarction

• Initial IV phase: Three 5 mg bolus injections at 2-minute intervals 3
• Oral maintenance:
  • If IV doses tolerated: 50 mg every 6 hours for 48 hours, then 100 mg twice daily 3, 2
  • If IV doses poorly tolerated: 25-50 mg every 6 hours based on tolerance 3

Special Populations and Precautions

Contraindications

• Marked first-degree AV block (PR interval >0.24 sec)
• Second or third-degree heart block without pacemaker
• Severe bronchial asthma
• Cardiogenic shock
• Severe heart failure (for initiation) 2
• Symptomatic bradycardia or hypotension 2

Dose Adjustments

• Elderly patients: Start with lower doses due to potential for decreased hepatic/renal function 3
• Hepatic impairment: Use lower initial doses with cautious titration 3
• Renal impairment: No dose adjustment typically required 3

Monitoring and Follow-up

• Monitor heart rate, blood pressure, and clinical status after each dose titration 1
• Target resting heart rate: 50-60 beats per minute unless limited by side effects 2
• Watch for signs of worsening heart failure, especially during initiation phase
• For patients with borderline bradycardia (HR 50-60 bpm), closer monitoring is essential 1

Clinical Pearls

• "Start low, go slow" approach is essential, particularly in heart failure patients 1
• Beta-blockers should be continued indefinitely in heart failure patients with reduced ejection fraction, even if symptoms improve 1
• The extended-release formulation (succinate) is preferred for heart failure based on mortality benefit evidence 2
• In one comparative trial, carvedilol showed greater mortality reduction than immediate-release metoprolol tartrate, but there have been no direct comparisons between carvedilol and metoprolol succinate at target doses 2
• Metoprolol succinate has been shown to reduce all-cause mortality by 34% in patients with heart failure 2, 1, 5

By following these dosing guidelines and monitoring protocols, metoprolol can effectively reduce morbidity and mortality in patients with hypertension, angina, and heart failure.