What is the equivalent metoprolol (beta-blocker) dose to Coreg (carvedilol) 50 mg twice a day?

Equivalent Metoprolol Dose to Carvedilol 50 mg Twice Daily

There is no established direct dose equivalency between carvedilol and metoprolol, as these are fundamentally different beta-blockers with distinct pharmacologic properties that cannot be reliably converted using a simple ratio. 1, 2

Why Direct Conversion Is Not Recommended

Beta-blockers are not interchangeable on a milligram-per-milligram basis because they differ substantially in:

• Receptor selectivity: Carvedilol is a non-selective beta-blocker (blocks both β1 and β2 receptors) plus alpha-1 blocker, while metoprolol is β1-selective at lower doses 3, 4
• Pharmacokinetic properties: Different half-lives, bioavailability, and duration of action 4
• Clinical trial evidence: Different formulations and doses were used in mortality trials 2, 4

Clinical Approach to Switching

If you must switch from carvedilol 50 mg twice daily to metoprolol, use metoprolol succinate (extended-release) starting at 50-100 mg once daily and titrate upward based on clinical response 1, 2:

Starting Strategy

• Begin with metoprolol succinate 50-100 mg once daily (not metoprolol tartrate) 1, 2
• Target dose is 200 mg once daily for heart failure patients, which is the evidence-based dose from the MERIT-HF trial 2
• Titrate by doubling the dose every 1-2 weeks if tolerated 2

Critical Monitoring During Transition

• Heart rate: Target resting HR 50-60 bpm 1
• Blood pressure: Maintain systolic BP >100 mmHg 1
• Signs of decompensation: Watch for worsening heart failure symptoms, increased dyspnea, edema, or weight gain 1

Important Caveats

Carvedilol 50 mg twice daily is a high dose (maximum approved dose is 25 mg twice daily for heart failure) 3. If the patient is truly on this dose, verify the indication and consider:

• Carvedilol remains non-selective at all clinically relevant doses, while metoprolol succinate becomes progressively less β1-selective at higher doses (≥200 mg) 3
• The COMET trial showed carvedilol superior to metoprolol tartrate (not succinate), but this does not necessarily apply to metoprolol succinate, which has different pharmacokinetics 4

Formulation Matters

Never use metoprolol tartrate as a substitute for carvedilol in heart failure patients:

• Metoprolol succinate (extended-release) reduced mortality by 34% in MERIT-HF 2
• Metoprolol tartrate showed inferior outcomes compared to carvedilol in COMET 2, 4
• The sustained-release formulation provides more consistent beta-blockade over 24 hours 5, 6

Practical Algorithm

1. Start metoprolol succinate 50 mg once daily 1, 2
2. Monitor HR, BP, and symptoms at 1-2 weeks 1
3. If stable, increase to 100 mg once daily 2
4. Continue titrating to target 200 mg once daily as tolerated 2
5. Hold or reduce dose if: HR <50 bpm with symptoms, systolic BP <100 mmHg with symptoms, or signs of decompensation 1

The goal is not dose equivalency but rather achieving optimal beta-blockade based on clinical endpoints (heart rate control, blood pressure, symptom improvement) rather than attempting a mathematical conversion. 1, 2