Equivalent Dosing for Metoprolol and Propranolol
The equivalent dosing ratio between metoprolol and propranolol is approximately 1:2.5, with 100 mg of metoprolol being approximately equivalent to 250 mg of propranolol. 1, 2, 3
Dosing Equivalence
- Metoprolol tartrate 50 mg twice daily is approximately equivalent to propranolol 80-100 mg twice daily 4, 1
- Metoprolol succinate (extended-release) 100 mg once daily is equivalent to metoprolol tartrate 100 mg (50 mg twice daily) 5
- Metoprolol tartrate 100 mg daily is approximately equivalent to propranolol 200-250 mg daily 2, 3
- When converting between these medications, a ratio of approximately 1:2.5 (metoprolol:propranolol) should be used 1, 3
Formulation Considerations
- Metoprolol is available in two salt forms: tartrate (immediate-release) and succinate (extended-release) 5
- Metoprolol tartrate is typically dosed twice daily, while metoprolol succinate is dosed once daily 6
- Propranolol is available in immediate-release form (dosed 2-3 times daily) and extended-release form (dosed once daily) 4
- A 100 mg metoprolol succinate (extended-release) tablet contains 95 mg of metoprolol succinate and is considered equivalent to 100 mg metoprolol tartrate 5
Clinical Dosing Guidelines
Metoprolol Dosing:
- Initial dosing of metoprolol tartrate: 25-50 mg twice daily 6
- Initial dosing of metoprolol succinate: 50-200 mg once daily 6
- Maximum dose: 200 mg daily for metoprolol tartrate and 400 mg daily for metoprolol succinate 6
- For heart failure, target dose of metoprolol succinate is 200 mg once daily 4
Propranolol Dosing:
- Usual dosing for propranolol: 20-80 mg twice daily 4
- For angina, propranolol is typically dosed at 80-320 mg daily in divided doses 4, 1
Intravenous Administration
- IV metoprolol: 5 mg increments given over 1-2 minutes, repeated every 5 minutes to a maximum of 15 mg 4, 7
- After IV metoprolol, transition to oral therapy with 25-50 mg every 6 hours for 48 hours, then maintenance dose of up to 100 mg twice daily 4, 7
- Monitor heart rate, blood pressure, ECG, and listen for rales and bronchospasm during IV administration 7
Special Considerations
- Metoprolol is beta-1 selective, making it potentially safer in patients with reactive airway disease, though caution is still warranted 4, 6
- Propranolol is non-selective (blocks both beta-1 and beta-2 receptors) and should be avoided in patients with asthma or COPD 4
- Both medications should be used cautiously in patients with heart failure, with careful titration and monitoring 4, 6
- Abrupt discontinuation of either medication should be avoided to prevent rebound hypertension or worsening angina 1, 7
Monitoring Parameters
- Target resting heart rate: 50-60 beats per minute unless limiting side effects occur 4, 7
- Monitor blood pressure and heart rate at each visit 6
- Watch for signs of worsening heart failure or bronchospasm, particularly during initiation 6, 7
Remember that individual patient factors may influence the optimal dosing equivalence, and close monitoring during conversion is essential 1.