Toprol (Metoprolol) Dosing
For heart failure with reduced ejection fraction (HFrEF), metoprolol succinate extended-release should be initiated at 12.5-25 mg once daily and titrated every 2 weeks to a target dose of 200 mg once daily, while for hypertension, metoprolol tartrate is typically started at 25-50 mg twice daily with a maximum of 200 mg daily. 1, 2, 3
Heart Failure with Reduced Ejection Fraction (HFrEF)
Metoprolol succinate extended-release (CR/XL) is the only metoprolol formulation proven to reduce mortality in heart failure—metoprolol tartrate does not have this evidence. 1, 2
Starting Dose
Titration Schedule
- Double the dose every 2 weeks if the previous dose is well tolerated 1
- Progression: 12.5 mg → 25 mg → 50 mg → 100 mg → 200 mg once daily 2
- Target dose is 200 mg once daily, which achieved a 34% reduction in all-cause mortality in the MERIT-HF trial 1, 4
Minimum Effective Dosing
- Aim for at least 50% of target dose (100 mg daily minimum) if the full target cannot be achieved, as dose-response relationships exist for mortality benefit 1, 2
- Even lower doses provide benefit if target doses cannot be tolerated 1, 2
Hypertension
Metoprolol Tartrate (Immediate-Release)
- Initial dose: 25-50 mg twice daily 2, 5
- Maximum dose: 200 mg daily in divided doses 2, 5
- Increase gradually every 1-2 weeks if blood pressure control is inadequate 5
Metoprolol Succinate (Extended-Release)
Important caveat: Beta-blockers are not recommended as first-line agents for hypertension unless the patient has ischemic heart disease or heart failure 2
Acute Myocardial Infarction
Early IV Treatment
- 5 mg IV bolus over 1-2 minutes, repeated every 5 minutes for a total of 3 doses (15 mg maximum) 3
- Monitor blood pressure, heart rate, and ECG continuously during IV administration 3
Transition to Oral Therapy
- Begin 50 mg orally every 6 hours starting 15 minutes after the last IV dose if the patient tolerates the full IV dose 3
- Continue for 48 hours, then transition to 100 mg twice daily for maintenance 3
- For patients who do not tolerate the full IV dose, start 25-50 mg orally every 6 hours depending on degree of intolerance 3
Atrial Fibrillation Rate Control
- Metoprolol tartrate: 25-100 mg twice daily 5
- Metoprolol succinate: 50-400 mg once daily 5
- Target resting heart rate of 50-60 beats per minute unless limiting side effects occur 5
Absolute Contraindications
- Signs of heart failure or low output state 3
- PR interval >0.24 seconds or second/third-degree heart block 3
- Active asthma or reactive airways disease 3
- Cardiogenic shock risk factors: systolic BP <120 mmHg, heart rate >110 or <60 bpm, age >70 years 5, 3
Critical Monitoring Parameters
- Heart rate and blood pressure at each visit and during any IV administration 5, 3
- Signs of worsening heart failure: increased dyspnea, weight gain, peripheral edema 1
- Daily weights for heart failure patients—increase diuretic if weight increases by 1.5-2.0 kg over 2 days 2
Common Pitfalls to Avoid
- Never use metoprolol tartrate for heart failure—only metoprolol succinate extended-release has mortality benefit 1, 2
- Avoid abrupt discontinuation, which can cause rebound hypertension or worsening ischemia 2, 5
- Do not underdose—many clinicians maintain patients on suboptimal doses due to fear of side effects, but achieving at least 50% of target dose is critical for mortality benefit 1, 2
- For worsening congestion during titration: Double the diuretic dose first, and only halve the beta-blocker dose if increasing diuretic fails 1, 2
- For marked fatigue or bradycardia <50 bpm with worsening symptoms: Halve the beta-blocker dose 1, 2
Special Populations
Hepatic Impairment
- Metoprolol blood levels increase substantially with hepatic impairment 3
- Initiate at low doses with cautious gradual titration 3
Renal Impairment
- No dose adjustment required 3
Geriatric Patients
- Use low initial starting doses given greater frequency of decreased hepatic, renal, or cardiac function 3