What is the losartan (angiotensin II receptor antagonist) equivalent dose of lisinopril (angiotensin-converting enzyme inhibitor) 20mg daily?

Losartan Equivalent of Lisinopril 20mg Daily

For lisinopril 20mg daily, the equivalent losartan dose is 50-100mg daily, with 50mg being the standard starting equivalent and 100mg being the target dose for optimal cardiovascular outcomes. 1

Dosing Equivalence Table

The American Heart Association, American College of Cardiology, and Heart Failure Society of America provide the following conversion guidance 1:

Lisinopril Dose	Losartan Equivalent
10-20 mg	50 mg
20-40 mg	100 mg

Clinical Approach to Conversion

Start with losartan 50mg once daily when converting from lisinopril 20mg, then titrate to 100mg daily based on blood pressure response and tolerability. 1

Rationale for Higher Target Dosing

• The target dose of lisinopril is 20-40mg daily, while the target dose of losartan is 50-150mg daily for heart failure management 1
• Clinical trials demonstrate that higher doses of losartan (100-150mg daily) provide superior cardiovascular outcomes compared to lower doses 2, 1
• The HEAAL trial showed a 10% relative risk reduction in death or heart failure hospitalization with losartan 150mg daily versus 50mg daily 2, 1

Comparative Efficacy Evidence

• Research studies demonstrate that losartan 50mg once daily produces similar antihypertensive effects to enalapril 20mg once daily 3
• Both losartan and enalapril (another ACE inhibitor) reduce albuminuria equally in hypertensive patients, with losartan 50mg showing comparable effects to enalapril 20mg 4

Titration Strategy

Adjust therapy no more frequently than every 2 weeks when uptitrating to target doses. 2

• Begin with losartan 50mg once daily 1
• If blood pressure remains uncontrolled after 2-4 weeks, increase to 100mg once daily 2, 1
• For heart failure patients with reduced ejection fraction, consider titration to 150mg daily for maximum mortality benefit 2, 1
• The maximum recommended daily dose is 100mg for hypertension, though 150mg may be used in heart failure 2, 5

Key Advantages of Losartan Over ACE Inhibitors

Losartan has a lower risk of angioedema and cough compared to ACE inhibitors like lisinopril, making it a suitable alternative for patients experiencing these side effects. 1

• The incidence of cough with losartan is similar to placebo, unlike ACE inhibitors 6
• Dizziness is the only adverse effect reported more frequently than placebo (2.4% vs 1.3%) 3
• Overall withdrawal rates due to adverse effects are lower with losartan than placebo (2.3% vs 3.7%) 3

Critical Safety Considerations During Conversion

Never combine losartan with lisinopril or any other ACE inhibitor, as this increases the risk of hyperkalemia and renal dysfunction without additional benefit. 2, 1

• Monitor blood pressure during the transition period to ensure adequate control 1
• Check renal function and potassium levels within 1-2 weeks after initiating losartan, especially in patients with baseline renal impairment 2
• Avoid losartan in pregnancy, as it causes serious fetal toxicity in the second and third trimesters 5

Common Pitfall to Avoid

Underdosing is widespread in clinical practice, with less than 25% of patients ever titrated to target doses. 2

• Maximum cardiovascular benefit requires achieving target doses of 100-150mg daily, not just the initial 50mg starting dose 2, 1
• There is little evidence that medium-range doses approximate the benefits of target doses 2

Combination Therapy Option

If blood pressure remains uncontrolled on losartan 100mg alone, add hydrochlorothiazide 12.5-25mg daily for additive blood pressure-lowering effects. 2