Lisinopril to Losartan Conversion Equivalency
When converting from lisinopril to losartan, a 20 mg daily dose of lisinopril is approximately equivalent to 50-100 mg daily of losartan, with 50 mg being the standard starting dose and 100 mg being the target dose for optimal cardiovascular outcomes. 1
Dosing Equivalence Table
| Lisinopril Dose | Losartan Equivalent Dose |
|---|---|
| 2.5-5 mg | 25-50 mg |
| 10-20 mg | 50 mg |
| 20-40 mg | 100 mg |
Evidence-Based Conversion Rationale
- According to the 2022 AHA/ACC/HFSA guideline for heart failure management, the target dose of lisinopril is 20-40 mg daily, while the target dose of losartan is 50-150 mg daily 1
- Clinical trials have demonstrated that higher doses of losartan (150 mg daily) are superior to lower doses (50 mg daily) for cardiovascular outcomes, similar to findings with lisinopril in the ATLAS trial 1
- The HEAAL trial showed a 10% relative risk reduction in death or heart failure hospitalization with losartan 150 mg daily compared to 50 mg daily, emphasizing the importance of achieving target doses 1, 2
Clinical Considerations for Conversion
- When switching from lisinopril to losartan, consider that losartan has a shorter half-life (2 hours) compared to its active metabolite E3174 (6-9 hours), while lisinopril has a longer half-life (12 hours) 3
- Losartan may be administered once daily at lower doses (50 mg) but may require twice-daily dosing at higher doses (150 mg total daily dose) for optimal blood pressure control 1, 4
- Unlike ACE inhibitors, ARBs like losartan have a lower risk of angioedema and cough, making them suitable alternatives for patients who experience these side effects with lisinopril 1, 4
Dosing in Special Populations
- No dosage adjustment is necessary for losartan in patients with mild hepatic impairment or various degrees of renal insufficiency 3
- In heart failure patients, uptitration to target doses is recommended to achieve maximum mortality and morbidity benefits 1
- For hypertension management, losartan 50 mg daily is often the initial dose, with titration to 100 mg daily if needed for blood pressure control 1
Efficacy Considerations
- Both lisinopril and losartan effectively reduce proteinuria, increase serum albumin levels, and lower blood pressure in patients with nephrotic syndrome 5
- In patients with heart failure, ARBs like losartan are considered alternatives to ACE inhibitors when patients cannot tolerate ACE inhibitors due to side effects 1
- The VALIANT trial showed that valsartan (another ARB) was non-inferior to captopril (an ACE inhibitor) in post-myocardial infarction patients with heart failure or left ventricular dysfunction 1
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
- Remember that maximum benefit from losartan may require higher doses (100-150 mg daily) than the initial starting dose of 50 mg daily 1, 2
Always consider individual patient factors such as comorbidities, concomitant medications, and previous response to therapy when converting between these medication classes.