What is the recommended dosing for Losartan (angiotensin II receptor antagonist)?

Losartan Dosing Recommendations

The standard dosing for losartan is 50 mg once daily initially, with titration to a maximum of 100 mg once daily as needed for blood pressure control in hypertension. 1

Standard Dosing for Different Indications

Hypertension

• Initial dose: 50 mg once daily
• Maximum dose: 100 mg once daily
• Special populations: 25 mg starting dose for patients with possible intravascular depletion (e.g., on diuretic therapy) 1

Hypertensive Patients with Left Ventricular Hypertrophy

• Initial dose: 50 mg once daily
• Titration: Can increase to 100 mg once daily based on blood pressure response
• Combination therapy: Hydrochlorothiazide 12.5 mg daily can be added and increased to 25 mg daily as needed 1

Nephropathy in Type 2 Diabetic Patients

• Initial dose: 50 mg once daily
• Maximum dose: 100 mg once daily 1

Heart Failure

• Higher doses (up to 150 mg daily) may provide greater benefits in heart failure patients, with a 10% relative risk reduction in death or heart failure hospitalization compared to lower doses 2

Dosing in Special Populations

Hepatic Impairment

• Mild to moderate impairment: 25 mg once daily starting dose
• Severe impairment: Not studied, use with caution 1

Renal Impairment

• No dosage adjustment necessary for various degrees of renal insufficiency 3
• Losartan has been shown to be effective and well-tolerated in patients with chronic renal disease, including those on hemodialysis 4

Pediatric Patients

• Starting dose: 0.7 mg/kg once daily (up to 50 mg total)
• Maximum dose: 1.4 mg/kg daily (not to exceed 100 mg)
• Not recommended for children under 6 years or with eGFR <30 mL/min/1.73m² 1

Dosing Considerations and Monitoring

• Losartan can be administered without regard to food 3
• Monitor blood pressure within 1-2 weeks after initiation or dose changes 2
• Monitor renal function when starting therapy or changing doses 2
• The pharmacokinetics of losartan are linear and dose-proportional 3
• Losartan is rapidly absorbed, reaching maximum concentrations 1-2 hours post-administration 3

Clinical Pearls

• While 50 mg is the standard starting dose, evidence suggests that 100 mg may provide optimal benefits for blood pressure control and renoprotection 2, 5
• In diabetic nephropathy, 100 mg daily was significantly more effective than 50 mg in reducing albuminuria (48% vs. 30% reduction) 6
• Losartan is contraindicated in pregnancy 3
• The active metabolite E3174 is 10-40 fold more potent than losartan with a half-life of 6-9 hours 3
• Losartan has minimal drug interactions and does not interact with hydrochlorothiazide, warfarin, or digoxin 3

Common Pitfalls to Avoid

• Underdosing: The 50 mg dose may be insufficient for optimal clinical benefits in many patients 5
• Not considering the higher dose range (100-150 mg) for heart failure patients 2
• Failing to start with a lower dose (25 mg) in patients at risk for intravascular volume depletion 1
• Not monitoring renal function and potassium levels, especially when initiating therapy

Remember that while the FDA-approved maximum dose for hypertension is 100 mg daily, clinical trials have shown benefits with doses up to 150 mg daily in specific conditions like heart failure 2.