What are the guidelines for switching from lisinopril (Angiotensin-Converting Enzyme (ACE) inhibitor) to losartan (Angiotensin II Receptor Blocker (ARB))?

From the Guidelines

When switching from lisinopril to losartan, start losartan within 24 hours of discontinuing lisinopril, with a typical conversion being from lisinopril 10-20 mg daily to losartan 50 mg daily, or from lisinopril 40 mg daily to losartan 100 mg daily, as per the doses outlined in the KDOQI clinical practice guidelines 1. To ensure a smooth transition, consider the following key points:

• Begin with a lower losartan dose (25-50 mg daily) if the patient has renal impairment, is elderly, or volume-depleted, to minimize potential adverse effects.
• Monitor blood pressure closely during the transition, especially in the first 1-2 weeks, as blood pressure control is crucial in patients with hypertension and chronic kidney disease, with higher levels of blood pressure associated with more rapid progression of kidney disease 1.
• Check renal function and potassium levels within 1-2 weeks after switching, as both ACE inhibitors and ARBs can affect kidney function and electrolyte balance.
• The transition from lisinopril to losartan is often made due to ACE inhibitor side effects like cough or angioedema, as ARBs have a similar mechanism but rarely cause these specific side effects, making them a suitable alternative for patients who experience these adverse effects.
• Both medications block the renin-angiotensin-aldosterone system but at different points - ACE inhibitors prevent the formation of angiotensin II while ARBs block its receptor binding, which is why losartan can be an effective substitute for lisinopril in managing hypertension and slowing the progression of kidney disease 1.
• Patients should continue taking other antihypertensive medications during the transition unless otherwise instructed, and should report symptoms like dizziness, significant blood pressure changes, or swelling, to ensure their safety and the effectiveness of the treatment regimen.

From the FDA Drug Label

7.4 Dual Blockade of the Renin-Angiotensin System (RAS) Dual blockade of the RAS with angiotensin receptor blockers, ACE inhibitors, or aliskiren is associated with increased risks of hypotension, syncope, hyperkalemia, and changes in renal function (including acute renal failure) compared to monotherapy The Veterans Affairs Nephropathy in Diabetes (VA NEPHRON-D) trial enrolled 1448 patients with type 2 diabetes, elevated urinary-albumin-to-creatinine ratio, and decreased estimated glomerular filtration rate (GFR 30 to 89.9 mL/min), randomized them to lisinopril or placebo on a background of losartan therapy and followed them for a median of 2. 2 years. Patients receiving the combination of losartan and lisinopril did not obtain any additional benefit compared to monotherapy for the combined endpoint of decline in GFR, end stage renal disease, or death, but experienced an increased incidence of hyperkalemia and acute kidney injury compared with the monotherapy group In most patients no benefit has been associated with using two RAS inhibitors concomitantly. In general, avoid combined use of RAS inhibitors. Closely monitor blood pressure, renal function, and electrolytes in patients on losartan and other agents that affect the RAS.

When switching from lisinopril (an ACE inhibitor) to losartan (an Angiotensin II Receptor Blocker (ARB)), it is essential to consider the potential risks associated with dual blockade of the Renin-Angiotensin System (RAS). The key points to consider are:

• Increased risk of hyperkalemia and acute kidney injury compared to monotherapy
• No additional benefit in using two RAS inhibitors concomitantly for most patients
• Avoid combined use of RAS inhibitors in general
• Closely monitor blood pressure, renal function, and electrolytes in patients on losartan and other agents that affect the RAS 2

From the Research

Guidelines for Switching from Lisinopril to Losartan

• The decision to switch from lisinopril, an Angiotensin-Converting Enzyme (ACE) inhibitor, to losartan, an Angiotensin II Receptor Blocker (ARB), should be based on individual patient needs and medical history 3.
• Patients with bilateral renal artery stenosis, severe congestive heart failure, and severe sodium and volume depletion should be cautious when switching, as their renal function may be angiotensin-dependent 3.
• Losartan may be used as an alternative to ACE inhibitors in patients with renal dysfunction, but renal function should be monitored closely, and losartan should be stopped if evidence of renal dysfunction becomes apparent 3.
• There is no evidence to suggest that losartan is better tolerated than ACE inhibitors from the standpoint of renal toxicity, and both medications may cause similar negative renal effects 3.

Considerations for Switching

• The ELITE trial showed a 10.5% incidence of losartan-induced renal dysfunction in elderly patients with congestive heart failure, similar to the incidence with captopril 3.
• A review of the literature revealed no controlled trials that specifically address whether losartan can be used as an alternative in patients with renal dysfunction associated with ACE inhibitors 3.
• Case reports suggest that losartan may cause reversible renal deterioration, similar to ACE inhibitors, and should be avoided in patients with bilateral renal artery stenosis or unilateral renal artery stenosis in a solitary kidney 3.

Comparison of Lisinopril and Losartan

• A study comparing valsartan (an ARB) with lisinopril found that both medications were effective in reducing blood pressure, but valsartan was associated with a significantly reduced risk of adverse events, especially cough 4.
• Another study found that losartan and lisinopril had similar effects on blood pressure reduction, but losartan was associated with a lower risk of angioedema 5.
• Animal studies have shown that both lisinopril and losartan can prevent angiotensin II-induced coronary vascular damage and myocyte necrosis, but the cardioprotective effects of ACE inhibition are dose-dependent and primarily related to the prevention of angiotensin I conversion to angiotensin II 6.