Timeframe to Stop Lisinopril and Start Losartan
When switching from lisinopril (ACE inhibitor) to losartan (ARB), you should wait at least 24 hours between stopping lisinopril and starting losartan to minimize the risk of adverse effects while maintaining blood pressure control.
Rationale for Switching Between ACE Inhibitors and ARBs
- ACE inhibitors and ARBs are both effective antihypertensive medications that work on the renin-angiotensin-aldosterone system (RAAS), but through different mechanisms 1
- Common reasons for switching from an ACE inhibitor to an ARB include:
Evidence-Based Switching Protocol
Immediate Switch Approach
- Research shows that switching directly from an ACE inhibitor to an ARB is generally safe and effective 3
- In a study of 177 hypertensive patients switching from captopril to losartan, there were no significant adverse events or symptomatic hypotension when switching immediately 3
Standard Recommendation
- Allow at least 24 hours between stopping lisinopril and starting losartan 4
- Losartan reaches maximum concentration in 1-2 hours after administration, with a half-life of 6-9 hours for its active metabolite E-3174 4
- This timeframe allows for adequate clearance of lisinopril while minimizing the period without RAAS blockade 4
Special Considerations
- For patients switching to sacubitril/valsartan (ARNI): A 36-hour washout period is required between stopping an ACE inhibitor and starting an ARNI due to increased risk of angioedema when these mechanisms overlap 1
- For patients with history of angioedema with ACE inhibitors: Consider a longer washout period of up to 6 weeks before starting an ARB 2
- For patients with kidney dysfunction: No dosage adjustment of losartan is necessary for various degrees of renal insufficiency 4
Dosing Considerations
- Losartan is typically started at 50 mg once daily, which can be administered without regard to meals 4
- Both once-daily and twice-daily regimens of losartan are effective, with some evidence suggesting twice-daily administration may provide better 24-hour blood pressure control 5
- Maximum recommended daily dose of losartan is 100 mg 4
Monitoring After Switching
- Monitor blood pressure within 1-2 weeks after switching to ensure adequate control 1
- Check serum creatinine and potassium within 1-2 weeks, especially in patients with pre-existing kidney dysfunction 1
- Some patients may experience an initial increase in creatinine (up to 50% above baseline) which is generally acceptable if stable 1
Potential Pitfalls to Avoid
- Never use ACE inhibitors and ARBs concurrently: This combination increases risk of adverse effects without additional benefit 1
- Temporary discontinuation during acute illness: Both ACE inhibitors and ARBs should be temporarily stopped during episodes of volume depletion (vomiting, diarrhea, etc.) to prevent acute kidney injury 1
- Medication adherence challenges: When switching medications, ensure the patient understands the new dosing schedule to maintain adherence 1
By following these guidelines, you can safely transition patients from lisinopril to losartan while maintaining effective blood pressure control and minimizing the risk of adverse effects.