What is the equivalent dose of Losartan (angiotensin II receptor antagonist) to Lisinopril (angiotensin-converting enzyme inhibitor) 20 mg in terms of blood pressure lowering effect?

Lisinopril 20 mg to Losartan Dose Equivalency

Lisinopril 20 mg is approximately equivalent to losartan 50-100 mg daily for blood pressure lowering effects, with 100 mg being the optimal target dose for maximum cardiovascular benefit. 1

Dosing Equivalence Table

• According to clinical guidelines, the following equivalence can be used when converting from lisinopril to losartan 1:
  • Lisinopril 2.5-5 mg = Losartan 25-50 mg
  • Lisinopril 10-20 mg = Losartan 50 mg
  • Lisinopril 20-40 mg = Losartan 100 mg

Evidence Supporting This Conversion

• The American Heart Association, American College of Cardiology, and Heart Failure Society of America recommend that a 20 mg daily dose of lisinopril is approximately equivalent to 50-100 mg daily of losartan 1
• Clinical trials have demonstrated that higher doses of losartan (100 mg daily) provide better cardiovascular outcomes than lower doses (50 mg daily), similar to findings with ACE inhibitors 1
• For optimal blood pressure control, losartan 50 mg is often the initial dose, with titration to 100 mg daily if needed 1, 2

Clinical Considerations When Converting

• Losartan has a different mechanism of action than lisinopril - it's an angiotensin II receptor blocker (ARB) rather than an ACE inhibitor 2
• Unlike ACE inhibitors, ARBs like losartan have a significantly lower risk of angioedema and cough, making them suitable alternatives for patients who experience these side effects with lisinopril 1
• Losartan 50 mg once daily produces similar antihypertensive effects to 20 mg of enalapril (another ACE inhibitor comparable to lisinopril) 2

Blood Pressure Lowering Efficacy

• Losartan demonstrates smooth antihypertensive effects throughout a 24-hour period following once-daily dosing 2, 3
• In clinical trials, losartan 50-100 mg daily showed comparable blood pressure reductions to other antihypertensive agents including calcium channel blockers and beta-blockers 2
• For isolated systolic hypertension, losartan-based regimens produce clinically significant reductions in systolic blood pressure comparable to amlodipine-based regimens (approximately 27-28 mmHg reduction) 4

Dosing in Special Populations

• In heart failure patients, uptitration to target doses (losartan 100 mg) is recommended to achieve maximum mortality and morbidity benefits 5, 1
• For patients with renal impairment, dose adjustments may be needed with lisinopril but are less critical with losartan 6
• The 2020 ACC/AHA guidelines indicate that for heart failure patients with reduced ejection fraction, the target dose of losartan is 100 mg daily 5

Common Pitfalls to Avoid

• Avoid simultaneous use of ACE inhibitors (like lisinopril) and ARBs (like losartan), as this combination increases risk of hyperkalemia and renal dysfunction without additional benefit 1
• When converting between medications, ensure adequate blood pressure monitoring during the transition period 1
• Maximum benefit from losartan may require higher doses (100 mg daily) than the initial starting dose of 50 mg daily 1, 2

Practical Approach to Conversion

1. For patients on lisinopril 20 mg daily, start with losartan 50 mg daily 1
2. Monitor blood pressure response after 2-4 weeks 1
3. If blood pressure control is inadequate, increase to losartan 100 mg daily 1, 2
4. For patients with heart failure, aim for the target dose of losartan 100 mg daily for optimal outcomes 5, 1