What is the equivalent dose of Metoprolol Tartrate (generic name) for a patient with hypertension or cardiovascular disease, currently taking Metoprolol Succinate 25mg twice daily (BID)?

Metoprolol Tartrate Equivalent Dose for Patient on Succinate 25mg BID

You should prescribe metoprolol tartrate 25mg twice daily (50mg total daily dose) as the equivalent to metoprolol succinate 25mg twice daily (50mg total daily dose). 1

Critical Formulation Clarification

Your patient is currently taking metoprolol succinate 25mg twice daily, which is incorrect dosing for this formulation. Metoprolol succinate is an extended-release formulation designed for once-daily administration only. 2, 3 The current regimen of 25mg BID provides a total daily dose of 50mg, but splits an extended-release medication inappropriately.

Direct Dose Conversion

• Metoprolol succinate 50mg once daily = Metoprolol tartrate 50mg total daily dose (typically given as 25mg twice daily). 1
• A 100mg metoprolol succinate tablet contains 95mg of metoprolol succinate and is considered equivalent to 100mg metoprolol tartrate in beta-blocking activity. 1
• The conversion is essentially 1:1 by total daily dose, though the pharmacokinetics differ significantly. 1, 4

Recommended Tartrate Dosing

Prescribe metoprolol tartrate 25mg twice daily (total 50mg/day) to match the current total daily dose of succinate. 5

• For hypertension, metoprolol tartrate dosing ranges from 100-200mg daily in divided doses (typically 50-100mg twice daily). 5, 2
• The starting dose of 25mg twice daily is conservative and appropriate for initial conversion. 5, 6
• Titrate upward every 1-2 weeks based on blood pressure and heart rate response, targeting a maximum of 200mg twice daily if needed. 5, 6

Important Pharmacokinetic Differences

• Metoprolol tartrate is immediate-release with a half-life of 3-7 hours, requiring twice-daily dosing for consistent beta-blockade. 3, 7
• Metoprolol succinate uses a controlled-release system that releases drug over approximately 20 hours, designed for once-daily dosing. 1, 3
• Despite the fourfold greater starting dose sometimes used with succinate, both formulations produce similar hemodynamic effects when given at equivalent total daily doses. 4

Critical Pitfall to Avoid

Never dose metoprolol succinate twice daily. 3 The extended-release formulation is specifically designed for once-daily administration. If your patient has been taking succinate 25mg BID, this represents either:

1. A prescribing error (should have been 50mg once daily), or
2. An attempt to use an inappropriate formulation for twice-daily dosing

Monitoring After Conversion

• Check blood pressure and heart rate within 1-2 weeks after switching formulations. 6
• Target resting heart rate of 50-60 bpm unless limiting side effects occur. 6
• Target blood pressure <130/80 mmHg for most patients with hypertension or cardiovascular disease. 5
• Watch for rebound hypertension or tachycardia during the transition period. 5, 2

Alternative Recommendation

Consider correcting to metoprolol succinate 50mg once daily instead of switching to tartrate. 2, 3 This provides the same total daily dose with the convenience of once-daily dosing and more consistent 24-hour beta-blockade. 1, 8 The succinate formulation may offer superior compliance and more stable blood pressure control throughout the 24-hour period. 8