What is an alternative to lisinopril (angiotensin-converting enzyme inhibitor) 10mg for a patient allergic to it, who is currently taking amlodipine (calcium channel blocker) 10mg?

Alternative to Lisinopril in ACE Inhibitor Allergy

Switch to an angiotensin receptor blocker (ARB) such as losartan 50mg daily or valsartan 160mg daily as the preferred alternative to lisinopril when a patient has an ACE inhibitor allergy. 1

Primary Recommendation: ARBs as First-Line Alternative

ARBs are the recommended alternative for patients who cannot tolerate ACE inhibitors due to allergy or adverse effects. 1 The 2018 ACC/AHA hypertension guidelines explicitly list multiple ARB options as alternatives to ACE inhibitors for blood pressure management 1:

• Losartan 50-100mg once daily 1
• Valsartan 80-320mg once daily 1
• Irbesartan 150-300mg once daily 1, 2
• Candesartan 8-32mg once daily 1
• Telmisartan 20-80mg once daily 1, 3

Critical Safety Consideration: Angioedema Risk

If the patient's "allergy" to lisinopril was angioedema, exercise extreme caution when prescribing an ARB. 1 While ARBs are generally considered safer alternatives, cross-reactivity can occur. The 2009 ACC/AHA heart failure guidelines specifically warn that "there are a number of patients who have also developed angioedema with ARBs and extreme caution is advised when substituting an ARB in a patient who has had angioedema associated with ACEI use." 1

Wait at least 6 weeks after discontinuing the ACE inhibitor before initiating an ARB in patients with prior angioedema. 1

Combination Therapy Advantage

Since your patient is already on amlodipine 10mg, adding an ARB creates a rational combination:

• The combination of amlodipine plus valsartan has demonstrated superior blood pressure control compared to monotherapy 4, 5
• This combination is well-tolerated and effective for stage 2 hypertension 4
• Amlodipine-ARB combinations are explicitly recommended in guidelines as effective dual therapy 1

Practical Dosing Algorithm

Start with moderate-dose ARB therapy given the patient is already on maximum-dose amlodipine:

1. Initiate losartan 50mg daily or valsartan 160mg daily 1
2. Titrate to maximum dose if blood pressure remains uncontrolled: losartan 100mg daily or valsartan 320mg daily 1
3. Monitor blood pressure at monthly intervals until control is achieved 3
4. Check renal function and potassium within 2-4 weeks of initiation (similar monitoring as with ACE inhibitors) 1

Why Not Other Alternatives?

Beta-blockers are not recommended as first-line alternatives unless the patient has specific indications like heart failure with reduced ejection fraction, post-MI status, or coronary artery disease 1. The guidelines clearly state beta-blockers are "not recommended as first-line agents unless the patient has IHD or HF." 1

Additional thiazide diuretics could be considered but would represent a third agent rather than a direct ACE inhibitor replacement 1. The ARB addresses the renin-angiotensin system blockade that lisinopril was providing.

Common Pitfalls to Avoid

• Do not combine ACE inhibitors with ARBs - this increases risk of hyperkalemia, hypotension, and renal dysfunction without improving outcomes 1
• Avoid ARBs in pregnancy - they carry the same fetal risk as ACE inhibitors 1, 2
• Monitor for hyperkalemia, especially if the patient has chronic kidney disease or is on potassium supplements 1
• Do not assume all "ACE inhibitor allergies" are true allergies - if the issue was cough (not angioedema), ARBs are excellent alternatives with minimal cross-reactivity 1