Is metoprolol indicated, what starting and target doses are recommended, and what contraindications and monitoring parameters should be considered for a patient with hypertension, chronic stable angina, post‑myocardial infarction therapy, and heart‑failure with reduced ejection fraction?

Metoprolol: Indications, Dosing, Contraindications, and Monitoring

Indications

Metoprolol is indicated for hypertension, chronic stable angina, post-myocardial infarction therapy, and heart failure with reduced ejection fraction (HFrEF), with specific formulations and dosing regimens required for each condition. 1

Specific Indications by Condition

• Heart Failure with Reduced Ejection Fraction (HFrEF): Only metoprolol succinate extended-release (CR/XL) is indicated, as it reduces all-cause mortality by 34%, cardiovascular mortality by 38%, and sudden death by 41% 1, 2
• Post-Myocardial Infarction: Beta-blocker therapy should be started and continued for 3 years minimum in all patients with normal left ventricular function, and indefinitely in those with ejection fraction ≤40% 1
• Hypertension: Metoprolol tartrate or succinate can be used, though beta-blockers are not first-line unless the patient has ischemic heart disease or heart failure 3, 4
• Chronic Stable Angina: Metoprolol 50-200 mg twice daily (tartrate) is effective for symptom control 1

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Starting and Target Doses

Heart Failure with Reduced Ejection Fraction

For HFrEF, initiate metoprolol succinate at 12.5-25 mg once daily and titrate every 2 weeks to the target dose of 200 mg once daily. 3, 4, 2

• Start at 12.5 mg once daily for NYHA class III-IV or 25 mg once daily for NYHA class II 3, 2
• Double the dose every 2 weeks if well tolerated: 12.5 mg → 25 mg → 50 mg → 100 mg → 200 mg once daily 3, 4
• Aim for at least 50% of target dose (100 mg daily minimum) if full target cannot be achieved, as dose-response relationships exist for mortality benefit 3, 4
• Critical: Only metoprolol succinate (CR/XL) has proven mortality reduction—metoprolol tartrate should NOT be used for heart failure 3, 4

Post-Myocardial Infarction

In hemodynamically stable post-MI patients, initiate oral metoprolol tartrate 25-50 mg every 6 hours for 48 hours, then transition to 100 mg twice daily maintenance. 1

• For patients receiving IV metoprolol (5 mg boluses × 3 over 15 minutes), start oral therapy 15 minutes after last IV dose at 25-50 mg every 6 hours 1
• After 48 hours, transition to maintenance dosing up to 100 mg twice daily 1
• Avoid IV metoprolol in patients with signs of heart failure, systolic BP <120 mmHg, heart rate >110 or <60 bpm, age >70 years, or Killip class II-III due to increased cardiogenic shock risk 1, 3

Hypertension

For hypertension, start metoprolol tartrate 25-50 mg twice daily or metoprolol succinate 50 mg once daily, titrating every 1-2 weeks to a maximum of 200 mg twice daily (tartrate) or 400 mg once daily (succinate). 3

• Initial dose: Metoprolol tartrate 25-50 mg twice daily OR metoprolol succinate 50 mg once daily 3
• Titrate every 1-2 weeks based on blood pressure response 3
• Maximum dose: 200 mg twice daily (tartrate) or 400 mg once daily (succinate) 3

Chronic Stable Angina

For angina, initiate metoprolol tartrate 50 mg twice daily and titrate to 50-200 mg twice daily based on symptom control. 1

• Usual dose range: 50-200 mg twice daily 1
• Target resting heart rate: 50-60 beats per minute unless limiting side effects occur 1

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Absolute Contraindications

Do not administer metoprolol in patients with decompensated heart failure, second- or third-degree AV block without a pacemaker, active asthma, symptomatic bradycardia (HR <50-60 bpm with symptoms), or systolic BP <100 mmHg with symptoms. 1, 3

Complete List of Absolute Contraindications

• Cardiac conduction abnormalities: PR interval >0.24 seconds, second- or third-degree AV block without functioning pacemaker 1, 3
• Hemodynamic instability: Signs of heart failure, low output state, decompensated heart failure, systolic BP <90-100 mmHg with symptoms 1, 3
• Bradycardia: Heart rate <50-60 bpm with symptoms (dizziness, lightheadedness, syncope) 1, 3
• Respiratory: Active asthma or severe reactive airway disease 1, 3
• Cardiogenic shock: Evidence of shock or high risk factors (age >70, Killip class II-III, systolic BP <120 mmHg, HR >110 or <60 bpm) 1, 3

Special Precautions

• Mild wheezing or COPD: Use reduced dose (12.5 mg) of cardioselective metoprolol rather than complete avoidance, with readily available bronchodilators 1, 3
• Pre-excited atrial fibrillation (WPW syndrome): Metoprolol may paradoxically accelerate ventricular response—avoid use 3

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Monitoring Parameters

During Initiation and Titration

Monitor heart rate, blood pressure, signs of congestion, and body weight at each visit during metoprolol titration. 3, 4

• Heart rate: Check at each visit; target 50-60 bpm for angina/post-MI, <80 bpm for atrial fibrillation 1, 3
  • If HR <50 bpm with worsening symptoms, halve the dose 3, 4
• Blood pressure: Target <130/80 mmHg for hypertension 3
  • If systolic BP <100 mmHg with symptoms (dizziness, lightheadedness), hold dose and reassess 3
• Signs of worsening heart failure: Increased dyspnea, fatigue, peripheral edema, weight gain >1.5-2.0 kg over 2 consecutive days 3, 4
• Daily weights: Instruct patients to weigh themselves daily and increase diuretic if weight increases by 1.5-2.0 kg over 2 days 3, 4

During IV Administration

For IV metoprolol, perform continuous ECG monitoring, frequent blood pressure and heart rate checks, and auscultation for rales and bronchospasm. 1, 3

• Continuous ECG monitoring throughout administration 1, 3
• Blood pressure and heart rate checks after each bolus 1, 3
• Auscultation for pulmonary rales (congestion) and bronchospasm 1, 3

Long-Term Monitoring

• Renal function and electrolytes: Check 1-2 weeks after initiation and after final dose titration, especially if on concurrent ACE inhibitors or ARBs 3, 4
• Symptoms: Monitor for fatigue, dizziness, or weakness, which may appear within 2-3 weeks 3
• Clinical response: Full beta-blocker benefits may require 2-3 months to become apparent 3

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Critical Warnings and Common Pitfalls

Never Abruptly Discontinue Metoprolol

Abrupt discontinuation of metoprolol can cause severe exacerbation of angina, myocardial infarction, ventricular arrhythmias, and is associated with a 2.7-fold increased risk of 1-year mortality. 3

• If discontinuation is necessary, taper by reducing dose by 25-50% every 1-2 weeks under close surveillance 3
• One study reported 50% mortality rate with abrupt cessation 3

Avoid Early IV Metoprolol in High-Risk MI Patients

The COMMIT trial demonstrated that early IV metoprolol increases cardiogenic shock by 11 per 1,000 patients, particularly in those with hemodynamic compromise. 1, 3

• Oral initiation within 24 hours is preferred over IV in hemodynamically stable patients 1
• Reserve IV metoprolol for specific indications: hypertensive crisis, ongoing ischemia, or tachyarrhythmias in stable patients 3

Formulation Matters for Heart Failure

Only metoprolol succinate extended-release has proven mortality reduction in heart failure—metoprolol tartrate should never be used for this indication. 3, 4

• The COMET trial showed carvedilol superior to metoprolol tartrate, confirming not all beta-blockers or formulations are equivalent 4

Drug Interactions

Combining metoprolol with other AV nodal blocking agents (digoxin, diltiazem, verapamil, amiodarone) can cause profound bradycardia. 3

• Monitor heart rate closely when combining these medications 3
• Consider dose reduction of one or both agents if symptomatic bradycardia develops 3

Underdosing is Common

Fewer than 25% of patients in real-world practice are titrated to target doses, compared to 64% in clinical trials—aggressive uptitration is essential for mortality benefit. 4

• Aim for at least 50% of target dose (100 mg daily for HFrEF) to achieve optimal outcomes 3, 4
• Some beta-blocker is better than no beta-blocker, but higher doses confer greater benefit 3, 4