What is the equivalent dose of Losartan for a patient taking 40 mg of Lisinopril (Angiotensin-Converting Enzyme Inhibitor)?

Lisinopril 40 mg to Losartan Conversion

The equivalent dose of losartan for a patient taking 40 mg of lisinopril is 100 mg daily. 1, 2

Dose Equivalence Rationale

• According to clinical guidelines, when converting from an ACE inhibitor (lisinopril) to an ARB (losartan), specific dose equivalence must be considered for optimal therapeutic effect 1
• The American College of Cardiology guidelines indicate that the target dose of lisinopril is 20-40 mg daily, which corresponds to losartan 100 mg daily as the equivalent therapeutic dose 2
• Clinical trials support that losartan 100 mg daily provides optimal blood pressure reduction and renoprotective effects comparable to higher doses of ACE inhibitors 3

Conversion Process

• When switching from lisinopril to losartan, start with losartan 50 mg daily and titrate up to the target dose of 100 mg daily 2
• Titration should occur gradually, typically every 2 weeks, based on blood pressure response and tolerability 2
• Monitor for hypotension, changes in renal function, and hyperkalemia during the transition period 1

Clinical Considerations

• Losartan has a favorable pharmacokinetic profile with once-daily dosing, reaching maximum concentrations 1-2 hours after administration 4
• Unlike lisinopril, losartan undergoes hepatic metabolism with approximately 14% converted to its active metabolite E-3174, which is 10-40 times more potent than the parent compound 4
• For patients with heart failure, clinical evidence supports that losartan 100 mg daily is the optimal dose for cardiovascular protection 2
• For patients with diabetic nephropathy, studies have demonstrated that losartan 100 mg provides significantly better renoprotection than 50 mg, with no additional benefit at 150 mg 3

Important Caveats

• Avoid simultaneous use of ACE inhibitors and ARBs as this combination increases the risk of hyperkalemia and renal dysfunction 2
• No dosage adjustment of losartan is necessary for patients with mild hepatic impairment or various degrees of renal insufficiency 4
• Both medications are contraindicated in pregnancy; women of childbearing age should use reliable contraception 5
• The maximum recommended daily dose of losartan is 100 mg, which can be given as a once-daily dose or by splitting into two doses 4

Special Populations

• For pediatric patients, losartan dosing starts at 0.7 mg/kg per day (up to 50 mg) and can be increased to 1.4 mg/kg per day (up to 100 mg) 5
• In elderly patients, no initial dosage adjustment is required, but closer monitoring during the transition is recommended 4