What are the recommended doses of losartan (Angiotensin II Receptor Blocker) for patients with hypertension?

Recommended Dosing of Losartan for Hypertension

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

Standard Dosing for Adults with Hypertension

• Initial dose: 50 mg once daily 1
• Maximum dose: 100 mg once daily 1
• Special populations requiring lower initial dose: 25 mg once daily
  • Patients with possible intravascular depletion (e.g., on diuretic therapy) 1
  • Patients with mild-to-moderate hepatic impairment 1

Dosing Considerations

Efficacy

• Once-daily dosing provides 24-hour blood pressure control due to losartan's active metabolite E3174, which has a half-life of 6-9 hours 2
• Losartan 50-100 mg once daily as monotherapy lowers blood pressure to a similar degree as enalapril, atenolol, and felodipine extended release 3

Special Populations

• Elderly patients: Standard dosing is effective; no specific dose adjustment required based on age alone 4
• Renal impairment: No dosage adjustment is necessary for patients with various degrees of renal insufficiency 2
  • Losartan has been shown effective in patients with mild renal insufficiency (30-60 mL/min/1.73 m²), moderate to severe renal insufficiency (10-29 mL/min/1.73 m²), and even those on hemodialysis 5
• Hepatic impairment:
  • Mild-to-moderate: Start with 25 mg once daily 1
  • Severe: Not studied; use with caution 1

Specific Conditions

• Hypertensive patients with left ventricular hypertrophy:

  • Initial dose: 50 mg once daily
  • Consider adding hydrochlorothiazide 12.5 mg daily and/or increasing losartan to 100 mg once daily based on blood pressure response 1

• Nephropathy in Type 2 Diabetic Patients:

  • Initial dose: 50 mg once daily
  • Increase to 100 mg once daily based on blood pressure response 1
  • Some evidence suggests 100 mg may be the optimal dose for renoprotection in diabetic nephropathy 6

Combination Therapy

• If blood pressure is not controlled with a two-drug combination, a three-drug combination is recommended, usually including a RAS blocker (such as losartan), a dihydropyridine CCB, and a thiazide/thiazide-like diuretic 7
• Fixed-dose single-pill combinations are recommended when using combination therapy 7

Common Pitfalls and Caveats

1. Avoid combining with other RAS blockers: Combining two RAS blockers (e.g., losartan with an ACE inhibitor) is not recommended 7

2. Pregnancy contraindication: Losartan should be avoided in pregnancy, as it can cause serious fetal toxicity when given in the second and third trimesters 2

3. Monitoring:

   • Monitor blood pressure within 1-2 weeks after initiation or dose changes 8
   • Check renal function when initiating therapy, particularly in patients with pre-existing renal impairment 8

4. Drug interactions: While losartan has a favorable drug-drug interaction profile, it is metabolized by CYP3A4, 2C9, and 2C10 enzymes, so potential interactions should be considered 2

By following these dosing recommendations and considering the specific patient factors outlined above, losartan can be effectively and safely used to manage hypertension in most adult patients.