Metoprolol Dosing Recommendation
No, you should not prescribe 112.5 mg of metoprolol as this is not a standard dosage according to current guidelines.
Standard Metoprolol Dosing
According to the 2017 ACC/AHA guidelines for hypertension management, metoprolol is available in two formulations with specific dosing ranges 1:
- Metoprolol tartrate: 100-200 mg daily, administered in 2 divided doses
- Metoprolol succinate (extended-release): 50-200 mg daily, administered once daily
Appropriate Dosing Options
For patients requiring a dose between 100-125 mg:
- Metoprolol tartrate: Use 50 mg tablets and prescribe either 100 mg (50 mg twice daily) or 125 mg (50 mg in morning, 75 mg in evening)
- Metoprolol succinate: Use 100 mg tablets or a combination of 50 mg + 25 mg tablets for a 75 mg dose
Clinical Considerations
Indication-Specific Dosing
- Hypertension: Start with lower doses (25-50 mg twice daily for tartrate; 50-100 mg once daily for succinate) and titrate based on blood pressure response 1
- Heart Failure: Begin with low doses (12.5-25 mg) and carefully uptitrate to target doses 2
- Angina: 50-200 mg twice daily 2
Monitoring Parameters
- Heart rate (target reduction is an important marker of therapeutic effect)
- Blood pressure
- Signs of heart failure, especially during initiation in high-risk patients
- Symptoms of bronchospasm (despite beta-1 selectivity, can still affect airways) 2
Important Precautions
Contraindications
- Marked AV block
- Severe bradycardia
- Hypotension
- Decompensated heart failure
- Severe bronchospastic disease 1, 2
Drug Interactions
- Caution with concomitant use of verapamil or digoxin due to potential for additive effects on heart rate and conduction 1
- Interactions with CYP2D6 inhibitors may increase metoprolol levels 3
Practical Recommendation
If you need to prescribe a dose close to 112.5 mg:
- For metoprolol tartrate: Use 50 mg + 25 mg (75 mg) in the morning and 50 mg in the evening (total 125 mg daily)
- For metoprolol succinate: Use 100 mg once daily or 50 mg + 75 mg (125 mg) once daily
Remember that abrupt discontinuation should be avoided; a gradual tapering schedule is recommended to prevent withdrawal effects, typically reducing the dose by half every week for 3 weeks 2.