What is the typical dose of Metoprolol (metoprolol succinate) XL for treating hypertension or heart failure?

Metoprolol XL Dosing

For heart failure with reduced ejection fraction (HFrEF), start metoprolol succinate extended-release (CR/XL) at 12.5-25 mg once daily and titrate every 2 weeks to a target dose of 200 mg once daily. 1, 2

Critical Formulation Distinction

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

Heart Failure Dosing Protocol

Starting Dose

• NYHA Class II: Begin with 25 mg once daily 4
• NYHA Class III-IV: Begin with 12.5 mg once daily 4

Titration Schedule

• Double the dose every 2 weeks if the previous dose is well tolerated 1, 2
• Standard progression: 12.5 mg → 25 mg → 50 mg → 100 mg → 200 mg once daily 2
• Titration period typically spans 6-8 weeks to reach target dose 4

Target Dose

• 200 mg once daily — this dose achieved a 34% reduction in all-cause mortality in the MERIT-HF trial 1, 2, 4
• If full target cannot be achieved, aim for at least 50% of target dose (100 mg daily minimum), as dose-response relationships exist for mortality benefit 2
• In MERIT-HF, 64% of patients achieved the target dose of 200 mg daily 2

Hypertension Dosing

• For hypertension alone, metoprolol tartrate is typically used at 100-200 mg daily in divided doses 1
• Beta-blockers are not first-line agents for hypertension unless the patient has ischemic heart disease or heart failure 2

Mortality and Clinical Benefits

• 34% reduction in all-cause mortality 3, 4
• 38% reduction in cardiovascular mortality 2
• 41% reduction in sudden death 2
• 49% reduction in death from progressive heart failure 2
• 35% reduction in heart failure hospitalizations 2, 4
• Number needed to treat: 27 patients for 1 year to prevent 1 death 2

Monitoring During Titration

Essential Parameters

• Heart rate: reduce dose if <50 bpm with worsening symptoms 2
• Blood pressure: monitor for symptomatic hypotension 2
• Daily weights: increase diuretic if weight increases by 1.5-2.0 kg over 2 days 2
• Signs of congestion, dyspnea, peripheral edema 2

Managing Adverse Effects During Titration

For worsening congestion:

• First: Double the diuretic dose 2
• Second: Halve the metoprolol dose only if increasing diuretic fails 2

For marked fatigue or bradycardia:

• Halve the metoprolol dose 2

For symptomatic hypotension:

• First: Reduce or eliminate vasodilators (nitrates, calcium channel blockers) 2
• Second: Reduce diuretic dose if no congestion present 2
• Third: Temporarily reduce metoprolol dose by 50% 2

Prerequisites and Contraindications

Before Initiating

• Establish background ACE inhibitor or ARB therapy 2
• Patient must be in relatively stable condition without need for IV inotropic therapy 1
• Discontinue calcium-channel blockers (especially diltiazem and verapamil) due to negative inotropic effects 2

Absolute Contraindications

• Current or recent (within 4 weeks) heart failure exacerbation requiring hospitalization 2
• PR interval >0.24 seconds 2
• Second or third-degree heart block 1, 2
• Active asthma or reactive airways disease 2, 5
• Symptomatic bradycardia or heart rate <50 bpm 1

Risk Factors for Cardiogenic Shock

• Age >70 years 2
• Systolic BP <120 mmHg 2
• Heart rate >110 bpm or <60 bpm 2

Critical Pitfalls to Avoid

• Never abruptly discontinue metoprolol — this risks rebound myocardial ischemia, infarction, and arrhythmias 2
• Do not use metoprolol tartrate for heart failure — only metoprolol succinate CR/XL has mortality data 2, 3
• Do not withhold beta-blocker for asymptomatic low blood pressure — only symptomatic hypotension requires intervention 2
• Some beta-blocker is better than no beta-blocker when target doses cannot be achieved 2

Pharmacokinetics Relevant to Dosing

• Oral bioavailability approximately 50% due to first-pass metabolism 6
• Elimination half-life: 3-4 hours in extensive metabolizers, 7-9 hours in poor CYP2D6 metabolizers 6
• Poor CYP2D6 metabolizers (8% of Caucasians) exhibit several-fold higher plasma concentrations 6
• No dosage adjustment needed for renal impairment 6
• Hepatic impairment may prolong half-life up to 7.2 hours 6