What is the recommended dosing when transitioning a patient from lisinopril (Angiotensin-Converting Enzyme Inhibitor) to losartan (Angiotensin II Receptor Blocker)?

Transitioning from Lisinopril to Losartan: Dosing Recommendations

When transitioning a patient from lisinopril to losartan, start with losartan 25-50 mg once daily when switching from lisinopril 10-20 mg daily, or losartan 50-100 mg once daily when switching from lisinopril 20-40 mg daily. 1

Equivalent Dosing Guidelines

• The target dose of lisinopril is 20-40 mg once daily, while the target dose of losartan is 50-150 mg once daily 1
• For patients on lisinopril 10 mg daily, initiate losartan at 25-50 mg once daily 1
• For patients on lisinopril 20 mg daily, initiate losartan at 50 mg once daily 1
• For patients on lisinopril 40 mg daily, initiate losartan at 100 mg once daily 1

Titration Recommendations

• After initiating losartan, titrate the dose every 1-2 weeks based on blood pressure response, symptoms, vital signs, and laboratory findings 1
• Aim to achieve at least 50% of the target dose (50 mg daily for losartan) to ensure clinical benefit 1
• The maximum FDA-approved dose of losartan is 100 mg daily, though guidelines mention doses up to 150 mg daily 1
• No dosage adjustment is necessary for elderly patients or those with mild to moderate renal dysfunction 2

Clinical Considerations

• Monitor blood pressure closely during the transition period, as individual responses may vary 3
• Unlike ACE inhibitors, ARBs like losartan do not cause cough, making them suitable alternatives for patients who developed cough on lisinopril 1
• Losartan has a favorable drug interaction profile and can be administered without regard to food 4
• The pharmacokinetics of losartan are linear and dose-proportional 4

Monitoring Parameters

• Check renal function and serum potassium within 1-2 weeks after initiating losartan, especially in patients with:
  • Pre-existing hypotension 1
  • Hyponatremia 1
  • Diabetes mellitus 1
  • Azotemia 1
  • Those taking potassium supplements 1

Common Pitfalls to Avoid

• Avoid abrupt discontinuation of lisinopril before starting losartan, as this can lead to clinical deterioration 1
• Do not use losartan in pregnant patients or those planning pregnancy 4
• Be cautious with concomitant use of potassium-sparing diuretics, potassium supplements, or potassium-containing salt substitutes due to risk of hyperkalemia 1
• Once-daily dosing of losartan is generally as effective as twice-daily dosing at the same total daily dose, so prefer once-daily dosing for better adherence 3, 5

By following these recommendations, you can safely and effectively transition patients from lisinopril to losartan while maintaining blood pressure control and minimizing adverse effects.