What is the recommended dosage and treatment guidelines for losartan (Angiotensin II Receptor Blocker) in patients with hypertension?

Losartan Dosage and Treatment Guidelines for Hypertension

The recommended starting dose of losartan for hypertension is 50 mg once daily, with titration to a maximum of 100 mg once daily as needed to control blood pressure. 1

Initial Dosing and Titration

• Starting dose: 50 mg once daily for most adults with hypertension 1
• Lower starting dose (25 mg) recommended for:
  • Patients with possible intravascular depletion (e.g., on diuretic therapy) 1
  • Patients with mild-to-moderate hepatic impairment 1
• Maximum dose: 100 mg once daily 1
• Titration should be based on blood pressure response, with dosage adjustments typically made after 2-4 weeks

Special Populations

• Renal impairment: No initial dosage adjustment necessary for various degrees of renal insufficiency 2
• Hepatic impairment:
  • Mild-to-moderate: Start with 25 mg once daily 1
  • Severe: Not studied, use with caution 1
• Elderly: No specific dosage adjustment required based on age alone 2
• Pediatric patients:
  • 6 years and older: 0.7 mg/kg once daily (up to 50 mg total) 1
  • Not recommended for children <6 years or with eGFR <30 mL/min/1.73m² 1

Specific Indications and Dosing

• Hypertension with left ventricular hypertrophy:
  • Start with 50 mg once daily 1
  • Consider adding hydrochlorothiazide 12.5 mg daily and/or increasing losartan to 100 mg daily based on blood pressure response 1
• Diabetic nephropathy:
  • Start with 50 mg once daily 1
  • Increase to 100 mg once daily based on blood pressure response 1, 3
  • Studies show 100 mg daily is more effective than 50 mg for renoprotection 3

Monitoring and Follow-up

• Monitor blood pressure regularly to assess response
• Check serum potassium and renal function:
  • At baseline
  • Within 1-2 weeks of initiation or dose changes
  • Periodically during treatment
• Target blood pressure should generally be <140/90 mmHg if tolerated 4
• Re-evaluate patients with stage 1 hypertension within 1 month and those with stage 2 hypertension within 1 month of diagnosis 4

Combination Therapy

• If blood pressure remains uncontrolled on maximum losartan dose:
  • Add a calcium channel blocker (preferred) or thiazide/thiazide-like diuretic 5, 4
  • For resistant hypertension, consider adding spironolactone 25 mg daily (if serum potassium <4.5 mmol/L) 5
  • Alternative add-on options include eplerenone, amiloride, beta-blockers, or alpha-blockers 5

Precautions and Contraindications

• Avoid use in pregnancy (especially second and third trimesters) due to risk of fetal toxicity 2
• Use caution in patients with bilateral renal artery stenosis 4
• Monitor for hyperkalemia, especially in patients with:
  • Chronic kidney disease
  • Concomitant use of potassium-sparing diuretics
  • Potassium supplements

Effectiveness and Tolerability

• Losartan effectively reduces blood pressure with once-daily dosing 6
• Generally well-tolerated with fewer side effects than ACE inhibitors (less cough) 2
• In patients with hypertension and LVH, losartan has been shown to reduce stroke risk compared to atenolol 7, 8

Losartan can be administered without regard to meals and has a favorable drug interaction profile, with no clinically significant interactions with hydrochlorothiazide, warfarin, or digoxin 2.