Equivalent Dosage When Switching from Amlodipine 5 mg to Losartan
When switching from amlodipine 5 mg to losartan, the recommended starting dose is 50 mg once daily, with potential titration to 100 mg daily as needed for optimal blood pressure control. 1
Dosing Recommendations
- Initial losartan dose: 50 mg once daily
- Maximum losartan dose: 50-100 mg daily (for hypertension)
- Frequency: Once daily or divided into twice daily dosing if needed 2, 1
The American College of Cardiology/American Heart Association guidelines recommend a usual dose range for losartan of 50-100 mg daily for hypertension management, with 100 mg being the maximum FDA-approved dose for hypertension 2.
Medication Comparison
| Medication | Initial Dose | Maximum Dose | Frequency |
|---|---|---|---|
| Amlodipine | 2.5-5 mg | 10 mg | Once daily |
| Losartan | 25-50 mg | 50-100 mg | Once or twice daily |
Considerations When Switching
Mechanism of Action Differences
- Amlodipine is a calcium channel blocker (dihydropyridine)
- Losartan is an angiotensin II receptor blocker (ARB)
Monitoring Recommendations
- Monitor blood pressure within 1-2 weeks after switching medications 1
- Check renal function and potassium levels within 1-2 weeks, particularly in patients with:
Special Populations
- For patients with heart failure, losartan may be titrated to higher doses (up to 150 mg daily) as this has shown greater benefit in reducing mortality and heart failure hospitalizations 1
- For patients with inadequate 24-hour blood pressure control on once-daily dosing, splitting the dose into twice-daily dosing may be considered 2, 1
Potential Advantages of Losartan over Amlodipine
- Lower incidence of peripheral edema (2.5% with losartan vs. 24.0% with amlodipine) 3
- Fewer drug-related adverse events overall (25.5% with losartan vs. 43.8% with amlodipine) 3
- Fewer discontinuations due to adverse events (4.4% with losartan vs. 12.9% with amlodipine) 3
Common Side Effects to Monitor
- Losartan: Dizziness (most common drug-related adverse event at 6.0%) 3
- Amlodipine: Lower extremity edema (most common drug-related adverse event at 24.0%) 3
Cautions and Contraindications
- Use losartan with caution in patients with:
- Losartan is contraindicated in:
Efficacy Considerations
Both medications are effective for blood pressure control, but clinical studies have shown:
- In some studies, amlodipine showed greater overall reductions in both systolic and diastolic blood pressure compared to losartan 4
- However, combination therapy with amlodipine/losartan has shown superior efficacy compared to either agent alone 5, 6
When switching from amlodipine to losartan, careful monitoring is essential to ensure adequate blood pressure control is maintained.