What is the typical starting dose of losartan (angiotensin II receptor antagonist) and how is it adjusted?

Starting Losartan: Dosing and Titration

For hypertension, start losartan at 50 mg once daily and titrate to a maximum of 100 mg once daily based on blood pressure response. 1

Initial Dosing by Indication

Hypertension (Most Common)

• Standard starting dose: 50 mg once daily 1
• Reduced starting dose: 25 mg once daily in patients with possible intravascular depletion (e.g., those already on diuretics) 1
• Maximum dose: 100 mg once daily 1
• Can be taken without regard to food 2

Heart Failure with Reduced Ejection Fraction

• Starting dose: 50 mg once daily 3, 4
• Target dose: 150 mg once daily for optimal cardiovascular outcomes 3, 4
• The European Society of Cardiology guidelines specifically recommend titrating from 50 mg to 150 mg daily, as this higher dose provides superior mortality and hospitalization benefits compared to lower doses 3, 4
• The HEAAL trial demonstrated that 150 mg daily was superior to 50 mg daily, with a 10% relative risk reduction in death or heart failure hospitalization 4

Nephropathy in Type 2 Diabetes

• Starting dose: 50 mg once daily 1
• Target dose: 100 mg once daily based on blood pressure response 1, 5
• For diabetic nephropathy specifically, 100 mg daily provides optimal renoprotection and is significantly more effective than 50 mg in reducing albuminuria 5

Titration Strategy

Adjust dosage no more frequently than every 2 weeks to reach target or maximally tolerated doses 4

Titration Schedule:

• Week 0-2: Start at 50 mg once daily (or 25 mg if volume depleted) 1
• Week 2-4: Increase to 100 mg once daily if blood pressure not controlled 1
• Week 4+: For heart failure patients, consider further titration to 150 mg once daily 3, 4

Critical point: Higher doses provide greater benefits than lower doses, with little evidence that medium-range doses approximate the benefits of target doses 4. However, underdosing is widespread in clinical practice, with less than 25% of patients ever titrated to target doses 4.

Special Populations Requiring Dose Adjustment

Hepatic Impairment

• Mild-to-moderate hepatic impairment: Start at 25 mg once daily 1
• Severe hepatic impairment: Not studied, use with extreme caution 1

Pediatric Patients (≥6 years)

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

No Dose Adjustment Required:

• Elderly patients 2, 6
• Mild to moderate renal insufficiency 2
• Patients on hemodialysis (losartan is not removed during dialysis) 2

Combination Therapy Considerations

If blood pressure remains uncontrolled on losartan 100 mg daily, add hydrochlorothiazide 12.5-25 mg daily rather than exceeding 100 mg losartan for hypertension 4, 1

For hypertensive patients with left ventricular hypertrophy:

• Start losartan 50 mg once daily 1
• Add hydrochlorothiazide 12.5 mg daily 1
• Increase losartan to 100 mg once daily as needed 1
• Increase hydrochlorothiazide to 25 mg once daily based on response 1

Critical Safety Monitoring

Monitor within 1-2 weeks after initiation:

• Serum potassium (risk of hyperkalemia) 4
• Serum creatinine and renal function 4
• Blood pressure response 1

Avoid these combinations:

• Never combine losartan with ACE inhibitors - this increases risk of hyperkalemia and renal dysfunction 4
• Avoid triple therapy with ACE inhibitors and aldosterone antagonists 4

Common Pitfalls to Avoid

• Underdosing: Most patients never reach target doses despite evidence showing higher doses provide better outcomes 4
• Too rapid titration: Wait at least 2 weeks between dose adjustments 4
• Inadequate monitoring: Check potassium and creatinine within 1-2 weeks of starting, especially in patients with baseline systolic BP <80 mmHg or creatinine >3 mg/dL 4
• Using 50 mg as final dose in heart failure: This dose is inferior to ACE inhibitors for mortality reduction; target 150 mg daily 4