What is the recommended dose of metoprolol (metoprolol succinate) for adults?

Metoprolol Succinate Dosing for Adults

For most adult indications, metoprolol succinate should be initiated at 50 mg once daily and titrated to a target maintenance dose of 200 mg once daily, with a maximum dose of 400 mg daily. 1, 2

Standard Dosing by Indication

Hypertension

• Initial dose: 50 mg once daily 2
• Maintenance dose: 50-200 mg once daily 2
• Maximum dose: 400 mg once daily 1, 2
• Titration interval: Every 1-2 weeks based on blood pressure response 2

Heart Failure with Reduced Ejection Fraction (HFrEF)

• Initial dose: 12.5-25 mg once daily (start lower in NYHA class III-IV patients) 2, 3, 4
• Target dose: 200 mg once daily 2, 3, 4
• Maximum dose: 400 mg once daily 1
• Titration schedule: Increase dose every 2 weeks if tolerated 2, 3
• Critical principle: At least 50% of target dose (100 mg daily) should be achieved for optimal mortality reduction 2

The MERIT-HF trial demonstrated that this dosing strategy produces a 34% reduction in all-cause mortality, 38% decrease in cardiovascular mortality, and 41% decrease in sudden death 2, 4

Atrial Fibrillation Rate Control

• Initial dose: 50 mg once daily 2
• Maintenance dose: 50-400 mg once daily 1, 2
• Target heart rate: 50-80 bpm (resting) 2

Supraventricular Tachycardia (SVT)

• Initial dose: 50 mg once daily 1
• Maintenance dose: 50-200 mg once daily 1
• Maximum dose: 400 mg once daily 1

Acute Myocardial Infarction Protocol

IV Phase (Early Treatment)

• Dose: 5 mg IV bolus over 1-2 minutes 2, 5
• Repeat: Every 5 minutes as needed 2, 5
• Maximum total IV dose: 15 mg (three 5 mg boluses) 2, 5
• Monitoring required: Continuous blood pressure, heart rate, and ECG during administration 5

Transition to Oral Therapy

• Timing: 15 minutes after last IV dose 2, 5
• Initial oral dose: 50 mg every 6 hours for 48 hours (if full IV dose tolerated) 2, 5
• Alternative: 25 mg every 6 hours if partial IV intolerance 5
• Maintenance dose: 100 mg twice daily after initial 48 hours 5

Critical contraindications before IV administration: Signs of heart failure, low output state, systolic BP <120 mmHg, heart rate >110 bpm or <60 bpm, PR interval >0.24 seconds, second or third-degree heart block, active asthma, or age >70 years with multiple risk factors 2

Special Population Considerations

Women

• Recommended dose reduction: 50% of standard doses on average 2
• Rationale: Metoprolol exposure is 50-80% higher in women than men, resulting in greater heart rate and blood pressure reduction 2
• Evidence: Women with heart failure achieve optimal outcomes at 50% of guideline-recommended doses, with 30% lower risk of death or heart failure hospitalization 2

Elderly Patients (>65 years)

• Initial dose: Start at low end of dosing range 5
• Titration: Cautious gradual dose escalation 5
• Rationale: Greater frequency of decreased hepatic, renal, or cardiac function 5
• Example: In elderly women, 25 mg produces similar drug exposure to 100 mg in healthy young men 2

Hepatic Impairment

• Approach: Initiate at low doses with cautious gradual titration 5
• Rationale: Metoprolol blood levels increase substantially in hepatic impairment 5

Renal Impairment

• Dose adjustment: None required 5

Pharmacokinetic Advantages of Extended-Release Formulation

The extended-release metoprolol succinate formulation delivers metoprolol at a near-constant rate for approximately 20 hours, producing even plasma concentrations over 24 hours without marked peaks and troughs 6. This leads to consistent beta1-blockade over 24 hours while maintaining cardioselectivity at doses up to 200 mg daily 6.

Critical Precautions and Contraindications

Absolute contraindications: 1, 2

• AV block greater than first degree or SA node dysfunction (without pacemaker)
• Decompensated systolic heart failure (for acute administration)
• Active asthma or reactive airway disease
• Cardiogenic shock
• Severe hypotension

Common adverse effects: Hypotension, bradycardia, bronchospasm, fatigue 1, 2

Common Pitfalls to Avoid

• Never abruptly discontinue metoprolol: This can cause severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias, with 50% mortality rate in one study and 2.7-fold increased risk of 1-year mortality 2
• Never give full 15 mg IV dose rapidly or as single bolus: This significantly increases hypotension and bradycardia risk 2
• Do not skip gradual titration in heart failure: Treatment must be initiated at very low doses with gradual incremental increases every 2 weeks 2, 3
• Monitor closely during IV administration: Frequent checks of heart rate, blood pressure, continuous ECG monitoring, and auscultation for rales and bronchospasm are essential 2