What is the recommended dose of metoprolol (beta-blocker) for various medical conditions?

Metoprolol Dosing Recommendations

Heart Failure with Reduced Ejection Fraction (HFrEF)

For heart failure, use only metoprolol succinate extended-release (CR/XL), starting at 12.5-25 mg once daily and titrating every 2 weeks to a target dose of 200 mg once daily. 1, 2

Critical Formulation Distinction

• Only metoprolol succinate extended-release (CR/XL) reduces mortality in heart failure—metoprolol tartrate (immediate-release) has not demonstrated this benefit and should not be used for HFrEF 1, 2, 3
• The three evidence-based beta-blockers proven to reduce mortality in HFrEF are bisoprolol, carvedilol, and sustained-release metoprolol succinate 2

Titration Schedule

• Start at 12.5 mg once daily for severe heart failure or 25 mg once daily for mild-moderate heart failure 1, 2
• Double the dose every 2 weeks if well tolerated: 12.5 mg → 25 mg → 50 mg → 100 mg → 200 mg once daily 1, 2
• Target dose of 200 mg once daily achieved a 34% reduction in all-cause mortality in the MERIT-HF trial 2, 3
• If full target dose cannot be tolerated, aim for at least 50% of target dose (100 mg daily minimum), as dose-response relationships exist for mortality benefit 1, 2

Sex-Based Dosing Considerations

Women with HFrEF may achieve optimal outcomes at 50% of guideline-recommended doses compared to men. 4

• Women showed ~30% lower risk of death or heart failure hospitalization at only 50% of guideline-recommended doses, with no additional benefit when up-titrated to full doses 4
• Metoprolol exposure is 50-80% higher in women than men, producing greater heart rate and blood pressure reduction 4
• A 50% dose reduction for metoprolol is recommended on average in women to reduce adverse drug reactions while maintaining efficacy 4
• For elderly women, metoprolol doses of 15 mg produce similar drug exposure to 50 mg in healthy young men; 25 mg in elderly women equals 100 mg in healthy young men 4

Monitoring During Titration

• Monitor heart rate, blood pressure, signs of congestion, and symptoms of worsening heart failure at each visit 1, 2
• Check blood chemistry 12 weeks after initiation and 12 weeks after final dose titration 2
• Patients should weigh themselves daily and increase diuretic dose if weight increases by 1.5-2.0 kg over 2 days 2

Managing Adverse Effects During Titration

• For worsening congestion: First double the diuretic dose; only halve the metoprolol dose if increasing diuretic fails 2
• For marked fatigue or bradycardia <50 bpm with worsening symptoms: Halve the metoprolol dose 2
• For symptomatic hypotension: First reduce or eliminate vasodilators (nitrates, calcium channel blockers); second, reduce diuretics if no congestion; third, temporarily reduce metoprolol by 50% 2

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Hypertension

For hypertension, metoprolol tartrate is dosed at 25-50 mg twice daily initially, or metoprolol succinate extended-release 50-200 mg once daily, with maximum doses of 200 mg daily for tartrate and 400 mg daily for succinate. 1

Initial Dosing

• Metoprolol tartrate (immediate-release): 25-50 mg twice daily 1
• Metoprolol succinate (extended-release): 50-200 mg once daily 1
• Maximum dose: 200 mg daily for tartrate, 400 mg daily for succinate 1

Titration

• Increase gradually every 1-2 weeks if blood pressure control is not achieved 1
• Target blood pressure reduction should be at least 20/10 mmHg, ideally to <140/90 mmHg 1

Important Caveat

• Beta-blockers are not recommended as first-line agents for hypertension unless the patient has ischemic heart disease or heart failure 2

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Acute Myocardial Infarction

For acute MI, administer 5 mg IV over 1-2 minutes, repeated every 5 minutes for a maximum total dose of 15 mg, followed by oral therapy 15 minutes after the last IV dose. 1, 5

IV Administration Protocol

• Give 5 mg IV over 1-2 minutes 1, 5
• Repeat every 5 minutes as needed based on hemodynamic response 1, 5
• Maximum total IV dose: 15 mg 1, 5
• Monitor blood pressure, heart rate, and ECG continuously during IV administration 1, 5

Transition to Oral Therapy

• Start oral metoprolol tartrate 15 minutes after the last IV dose 1, 5
• For patients tolerating full IV dose: 50 mg every 6 hours for 48 hours, then 100 mg twice daily 5
• For patients with partial intolerance: 25-50 mg every 6 hours depending on degree of intolerance 5
• For severe intolerance: Discontinue metoprolol 5

Absolute Contraindications for IV Metoprolol in Acute MI

• Signs of heart failure, low output state, or increased risk for cardiogenic shock 1, 5
• Systolic BP <120 mmHg 1
• Heart rate >110 bpm or <60 bpm 1
• PR interval >0.24 seconds 1
• Second or third-degree heart block 1, 5
• Active asthma or reactive airways disease 1, 5
• Age >70 years with multiple risk factors 1

Risk-Benefit Consideration

• Early IV metoprolol reduces reinfarction by 5 per 1000 patients and ventricular fibrillation by 5 per 1000 patients 1
• However, it increases cardiogenic shock by 11 per 1000 patients, particularly in the first 24 hours 1
• The COMMIT trial showed increased risk of cardiogenic shock in high-risk patients 1

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Atrial Fibrillation Rate Control

For atrial fibrillation, use metoprolol tartrate 25-100 mg twice daily or metoprolol succinate 50-400 mg once daily, targeting a resting heart rate of 50-60 bpm. 1

Oral Dosing

• Metoprolol tartrate: 25-100 mg twice daily 1
• Metoprolol succinate (XL): 50-400 mg once daily 1
• Target resting heart rate: 50-60 bpm unless limiting side effects occur 1

IV Dosing for Acute Rate Control

• 5 mg IV over 1-2 minutes 1
• Repeat every 5 minutes as needed, maximum total dose 15 mg 1
• Transition to oral therapy 15 minutes after last IV dose: 25-50 mg every 6 hours for 48 hours 1

Contraindications

• Pre-excitation and atrial fibrillation (Wolff-Parkinson-White syndrome) 1
• Decompensated heart failure 1

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Frequent Premature Ventricular Contractions (PVCs)

For frequent PVCs, start metoprolol tartrate at 25 mg twice daily, with a maximum maintenance dose of 200 mg twice daily. 1

Dosing

• Initial dose: 25 mg twice daily 1
• For extended-release formulation: 50 mg once daily initially 1
• Maximum daily dose: 200 mg twice daily for tartrate, 400 mg for extended-release 1

Contraindications

• AV block greater than first degree or SA node dysfunction 1
• Decompensated systolic heart failure 1
• Hypotension 1
• Reactive airway disease or severe asthma 1
• Cardiogenic shock 1

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Supraventricular Tachycardia

For SVT, administer 5 mg IV over 1-2 minutes, repeated every 5 minutes as required to a maximum dose of 15 mg, titrating according to heart rate and blood pressure response. 1

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Special Populations

Elderly Patients

• Use low initial starting doses given greater frequency of decreased hepatic, renal, or cardiac function 5
• For elderly women, consider 15-25 mg doses to achieve equivalent drug exposure to standard doses in younger men 4

Hepatic Impairment

• Metoprolol blood levels increase substantially in hepatic impairment 5
• Initiate at low doses with cautious gradual titration according to clinical response 5

Renal Impairment

• No dose adjustment required 5

Pediatric Patients

• Safety and efficacy not established 5

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Critical Warnings

Abrupt Discontinuation

Never abruptly discontinue metoprolol, especially in patients with coronary artery disease—severe exacerbation of angina, myocardial infarction, and ventricular arrhythmias have been reported. 5

• When discontinuing chronically administered metoprolol, reduce dosage gradually over 1-2 weeks 5
• Beta-blocker withdrawal is associated with 2.7-fold increased risk of 1-year mortality compared to continuous use 1
• Abrupt discontinuation can cause 50% mortality rate in some studies 1
• Reduce metoprolol dose by approximately 25-50% every 1-2 weeks when tapering 1

Bronchospastic Disease

• Patients with bronchospastic disease should generally not receive beta-blockers 5
• If metoprolol must be used, use the lowest possible dose and consider three times daily dosing instead of twice daily to avoid higher plasma levels 5
• Bronchodilators, including beta-2 agonists, should be readily available 5

Bradycardia Management

• For symptomatic bradycardia (HR <60 bpm with symptoms): Reduce metoprolol dose by 50% 1
• Hold dose if HR consistently <45 bpm, or delay by 12 hours if HR 45-49 bpm 1
• Hold completely if systolic BP <100 mmHg with symptoms 1

Diabetes

• Beta-blockers may mask tachycardia occurring with hypoglycemia, though dizziness and sweating may not be significantly affected 5

Pheochromocytoma

• If used, must be given in combination with an alpha blocker, and only after the alpha blocker has been initiated 5
• Beta-blockers alone can cause paradoxical increase in blood pressure 5

Thyrotoxicosis

• Metoprolol may mask tachycardia of hyperthyroidism 5
• Avoid abrupt withdrawal, which might precipitate thyroid storm 5