What is the equivalent dose of losartan for a patient taking 10 mg of lisinopril (Angiotensin-Converting Enzyme (ACE) inhibitor)?

Equivalent Dose of Losartan for Patients Taking 10 mg of Lisinopril

For patients taking 10 mg of lisinopril, the equivalent dose of losartan is 50 mg once daily. 1

Dosing Equivalence and Rationale

According to the American College of Cardiology/American Heart Association guidelines, the following dose equivalents are established:

• Lisinopril 10 mg daily is considered 50% of the target dose (20 mg daily) for heart failure patients 2
• Losartan 50 mg daily is considered 50% of the target dose (100 mg daily) for heart failure patients 2

Therefore, when converting from lisinopril 10 mg to losartan, the appropriate equivalent dose is 50 mg once daily.

Dosing Considerations

• Initial dosing: Start with losartan 50 mg once daily when discontinuing lisinopril 10 mg 1
• Titration: If needed, losartan can be titrated up to 100 mg daily (FDA-approved maximum dose) 2
• Higher doses: Some guidelines recommend losartan doses up to 150 mg daily for optimal cardiovascular outcomes, particularly in heart failure patients 2, 1
• Monitoring: Check blood pressure and renal function within 1-2 weeks after switching 1

Clinical Evidence Supporting Conversion

The European Society of Cardiology guidelines provide evidence-based dosing recommendations that align with this conversion:

• Lisinopril target dose: 20 mg once daily
• Losartan target dose: 100 mg once daily (with evidence supporting up to 150 mg daily) 2

Important Considerations When Switching

• Pharmacokinetic differences:

  • Losartan is metabolized to an active metabolite (E-3174) that provides most of its antihypertensive effect 3
  • Losartan has a shorter half-life than lisinopril (6-9 hours vs 12.6 hours) 4, 3

• Dosing frequency:

  • Both medications are typically administered once daily 5
  • Recent evidence does not support improved effectiveness with twice-daily dosing for either medication 5

• Special populations:

  • No dosage adjustment is necessary for mild hepatic impairment or various degrees of renal insufficiency with losartan 3
  • Lisinopril requires dose adjustment when creatinine clearance is less than 30 mL/min 6

Potential Advantages of Switching

• Losartan may have a lower incidence of cough compared to ACE inhibitors like lisinopril 3, 7
• Losartan may be better tolerated in patients who experienced ACE inhibitor-induced cough 1

Cautions

• Both medications are contraindicated in pregnancy 2, 3
• Monitor for hypotension, hyperkalemia, and changes in renal function after switching 1
• Angioedema, though rare, can occur with both medications 7

Following this conversion guideline will help ensure appropriate blood pressure control and cardiovascular protection when switching from lisinopril to losartan.