What is the recommended approach for switching from lisinopril (Angiotensin-Converting Enzyme Inhibitor) to losartan (Angiotensin II Receptor Blocker) in a patient with a history of angioedema?

Switching from Lisinopril to Losartan in Patients with History of Angioedema

When switching from lisinopril to losartan in a patient with a history of angioedema, a 6-week washout period is recommended before initiating the ARB, with careful monitoring for recurrence of angioedema. 1

Risk Assessment and Considerations

• ACE inhibitors like lisinopril have a higher incidence of angioedema compared to ARBs, with black patients and smokers being at particularly higher risk 1, 2
• While ARBs are generally safer alternatives for patients who experienced angioedema with ACE inhibitors, there remains a modest risk of recurrent angioedema (2-17%) when switching to an ARB 1
• The mechanism of ACE inhibitor-induced angioedema involves bradykinin accumulation, while the mechanism for ARB-associated angioedema is less clear but may also influence bradykinin levels 1
• Case reports have documented angioedema associated with losartan use, including in patients with previous ACE inhibitor-induced angioedema 3, 4

Switching Protocol

1. Discontinue lisinopril immediately if the patient experienced angioedema while taking it 1
2. Implement a 6-week washout period between stopping the ACE inhibitor and starting losartan 1
3. Start losartan at a low dose (25-50 mg once daily) after the washout period 1
4. Monitor closely for signs of angioedema during the first weeks of therapy 1
5. Gradually titrate the losartan dose if needed and tolerated, up to 50-100 mg once daily 1

Special Considerations

• Risk factors for recurrent angioedema when switching to an ARB include:

  • Severity of the initial angioedema episode 1
  • Black race and smoking history 1
  • Time proximity between ACE inhibitor use and angioedema occurrence 3

• Alternative antihypertensive options if ARBs are contraindicated or not tolerated:

  • Calcium channel blockers
  • Thiazide diuretics
  • Beta-blockers (with caution, as rare cases of beta-blocker-induced angioedema have been reported) 5

Patient Education and Monitoring

• Educate patients about potential symptoms of angioedema (swelling of lips, tongue, face, or throat) and instruct them to seek immediate medical attention if these occur 6, 7
• Provide clear instructions on when to discontinue the medication and seek emergency care 1
• Schedule follow-up within 1-2 weeks after initiating losartan to assess for adverse effects 1
• Monitor blood pressure, renal function, and potassium during the transition period 1

Cautions and Contraindications

• ARBs should be used with extreme caution in patients with a history of angioedema associated with ACE inhibitors 1
• The decision to use an ARB should involve careful risk-benefit assessment considering the therapeutic need for angiotensin/renin inhibition versus the risk of recurrent angioedema 1
• Avoid ARNIs (angiotensin receptor-neprilysin inhibitors) in patients with a history of angioedema as they carry an increased risk 1