What is the recommended dosage and treatment protocol for Metoprolol (beta-blocker) in patients with hypertension or heart-related conditions?

Metoprolol Dosing and Treatment Protocol

For hypertension, start metoprolol tartrate at 25-50 mg twice daily or metoprolol succinate (extended-release) at 50-100 mg once daily, titrating every 1-2 weeks to a maximum of 200 mg daily for tartrate or 400 mg daily for succinate, targeting blood pressure <130/80 mmHg. 1

Initial Dosing by Indication

Hypertension

• Metoprolol tartrate (immediate-release): 25-50 mg twice daily initially 1
• Metoprolol succinate (extended-release): 50-100 mg once daily initially 1
• Titrate every 1-2 weeks based on blood pressure response 1
• Maximum dose: 200 mg daily for tartrate, 400 mg daily for succinate 1

Acute Myocardial Infarction

• IV phase: 5 mg IV bolus over 1-2 minutes, repeated every 5 minutes up to 3 doses (15 mg total maximum) 1, 2
• Transition to oral: Begin 50 mg orally every 6 hours starting 15 minutes after last IV dose, continue for 48 hours 1, 2
• Maintenance: 100 mg twice daily thereafter 1, 2
• Monitor blood pressure, heart rate, and ECG continuously during IV administration 2

Atrial Fibrillation Rate Control

• Metoprolol tartrate: 25-100 mg twice daily 1
• Metoprolol succinate: 50-400 mg once daily 1
• Target resting heart rate <80 bpm (strict control) or <110 bpm (lenient control) 1

Heart Failure with Reduced Ejection Fraction (HFrEF)

• Initial dose: 12.5-25 mg once daily of metoprolol succinate 1
• Target dose: 200 mg once daily 1
• Titrate slowly over weeks to months, as clinical response may take 2-3 months to fully manifest 1

Frequent PVCs

• Metoprolol tartrate: 25 mg twice daily initially, maximum 200 mg twice daily 1
• Metoprolol succinate: 50 mg once daily initially, maximum 400 mg daily 1

Absolute Contraindications

Do not administer metoprolol if any of the following are present: 1

• Signs of heart failure, low output state, or decompensated heart failure
• Systolic BP <120 mmHg (particularly for IV administration in acute MI)
• Heart rate >110 bpm or <60 bpm (for acute MI)
• PR interval >0.24 seconds
• Second or third-degree heart block without functioning pacemaker
• Active asthma or reactive airways disease
• Cardiogenic shock or high risk factors (age >70 years, Killip class II-III)

IV to Oral Conversion Protocol

For patients requiring conversion from oral to IV metoprolol: 1

• Start with 2.5-5 mg IV bolus over 1-2 minutes 1
• Repeat every 5 minutes as needed based on hemodynamic response 1
• Maximum total dose: 15 mg 1
• Do not give the full 15 mg as a single rapid bolus—this significantly increases hypotension and bradycardia risk 1
• Transition back to oral: Begin metoprolol tartrate 25-50 mg every 6 hours starting 15 minutes after last IV dose 1

Critical Monitoring Parameters

During IV Administration

• Continuous heart rate monitoring 1
• Continuous blood pressure monitoring 1
• Continuous ECG monitoring 1
• Auscultate for new rales (pulmonary congestion) 1
• Auscultate for bronchospasm 1

During Oral Therapy

• Blood pressure and heart rate at each visit 1
• Target resting heart rate: 50-60 bpm unless limiting side effects occur 1
• Monitor for signs of worsening heart failure (increased dyspnea, fatigue, edema, weight gain) 1
• Watch for symptomatic bradycardia (HR <60 bpm with dizziness or lightheadedness) 1
• Assess for hypotension (systolic BP <100 mmHg with symptoms) 1

Management of Adverse Effects

Symptomatic Bradycardia (HR <50 bpm with symptoms)

• Hold metoprolol immediately if systolic BP <100 mmHg with symptoms or signs of hypoperfusion 1
• Reduce dose by 50% if BP improves above 100 mmHg systolic and HR rises above 50 bpm without symptoms 1
• Consider atropine 0.5 mg IV every 3-5 minutes (maximum 3 mg total) for acute symptomatic bradycardia 1
• Never abruptly discontinue—this increases mortality risk 2.7-fold and can cause severe exacerbation of angina, MI, and ventricular arrhythmias 1, 3

Hypotension

• Hold dose if systolic BP <100 mmHg with symptoms 1
• Reduce dose by 50% once BP stabilizes 1
• Assess for signs of hypoperfusion (oliguria, altered mental status, cool extremities) 1

Tapering Protocol

When discontinuation is necessary, reduce dose by 25-50% every 1-2 weeks: 1

• Monitor for worsening heart failure symptoms (increased fatigue, shortness of breath) 1
• If symptoms worsen, return to previous dose before attempting more gradual taper 1
• For heart failure patients, use smaller incremental reductions 1
• Consider temporarily increasing diuretics or ACE inhibitors if worsening occurs 1

Special Population Considerations

Women

• Women may achieve optimal outcomes at 50% of standard guideline-recommended doses 1
• Metoprolol exposure is 50-80% higher in women than men 1
• Consider starting at lower doses (12.5 mg) to reduce adverse drug reactions while maintaining efficacy 1

Elderly Patients (>65 years)

• Start at low doses with cautious gradual titration 2
• Metoprolol 15 mg in elderly women produces similar exposure to 50 mg in healthy young men 1
• Monitor closely for decreased hepatic, renal, or cardiac function 2

Hepatic Impairment

• Initiate at low doses with cautious gradual titration 2
• Elimination half-life may be prolonged up to 7.2 hours depending on severity 2

Renal Impairment

• No dose adjustment required 2

Common Pitfalls to Avoid

• Never administer IV metoprolol in decompensated heart failure—this increases cardiogenic shock risk by 11 per 1000 patients 1
• Never use metoprolol in pre-excited atrial fibrillation (WPW syndrome)—it may paradoxically accelerate ventricular response 1
• Never give full 15 mg IV dose rapidly or as single bolus 1
• Never abruptly discontinue without tapering—associated with 50% mortality rate in one study 1
• Do not assume fever is benign in hospitalized patients; rule out sepsis and alcohol withdrawal before beta-blockade 1
• Avoid in patients with marked first-degree AV block (PR >0.24 seconds) without pacemaker 1

Alternative Agents When Metoprolol is Contraindicated

For Rate Control

• Diltiazem 120-360 mg daily (does not cause bradycardia, suitable for patients with reactive airway disease) 1
• Verapamil (avoid in severe LV dysfunction) 1

For Acute Situations

• Esmolol infusion 50-300 mcg/kg/min (ultra-short acting, allows rapid titration and reversal) 1