Starting Dose of Losartan
The standard starting dose of losartan is 50 mg once daily for most adults with hypertension, but should be reduced to 25 mg once daily in patients with possible intravascular volume depletion (e.g., those on diuretic therapy) or mild-to-moderate hepatic impairment 1.
Standard Adult Dosing
For typical adult hypertension:
- Start with 50 mg once daily 1
- Can be increased to a maximum of 100 mg once daily as needed for blood pressure control 2, 3, 1
- May be given as once-daily dosing or split into twice-daily dosing 2, 3
- Can be taken without regard to food 4
Dose Adjustments for Specific Populations
Volume-Depleted Patients
Start with 25 mg once daily if the patient has possible intravascular depletion 1. This specifically includes:
- Patients currently on diuretic therapy
- Patients with clinical signs of volume depletion
- This lower starting dose minimizes the risk of symptomatic hypotension, though first-dose hypotension risk with losartan is generally low 5
Hepatic Impairment
Start with 25 mg once daily in patients with mild-to-moderate hepatic impairment 1. The rationale is that plasma concentrations of losartan are 5 times higher and the active metabolite (E3174) is 1.7 times higher in these patients compared to healthy individuals 1. Losartan has not been studied in severe hepatic impairment and should be avoided in this population 1.
Renal Impairment
No dose adjustment is necessary for patients with renal insufficiency, including those with severe renal impairment (creatinine clearance 10-29 mL/min) 1, 6. The pharmacokinetics of losartan and its active metabolite E3174 remain stable across all degrees of renal function 6.
Important caveat: If a patient has both renal impairment AND volume depletion, start with 25 mg once daily due to the volume depletion status 1.
Elderly Patients
No dose adjustment required based on age alone 1, 5. The pharmacokinetics of losartan show no clinically significant age-related changes 4. Studies in elderly patients (including those ≥75 years) demonstrate similar safety and efficacy profiles compared to younger patients 5, 7.
Pediatric Dosing (Ages 6-16 Years)
- Start with 0.7 mg/kg once daily (up to 50 mg maximum) 1
- Adjust based on blood pressure response
- Maximum dose: 1.4 mg/kg or 100 mg daily (whichever is lower) 1
- Not recommended in children under 6 years or with eGFR <30 mL/min/1.73 m² 1
Special Clinical Scenarios
Hypertension with Left Ventricular Hypertrophy
Start with 50 mg once daily, then add hydrochlorothiazide 12.5 mg daily and/or increase losartan to 100 mg once daily, followed by increasing hydrochlorothiazide to 25 mg daily based on blood pressure response 1.
Type 2 Diabetic Nephropathy
Start with 50 mg once daily, then increase to 100 mg once daily based on blood pressure response 1.
Key Clinical Pearls
Combination therapy considerations: The losartan/hydrochlorothiazide 50 mg/12.5 mg combination is safe and effective, particularly in elderly patients, and provides superior blood pressure reduction compared to high-dose losartan monotherapy (100 mg) 7.
Monitoring: No routine dose adjustment needed based on renal function monitoring, as losartan and E3174 are not removed by hemodialysis 4. However, monitor for hyperkalemia, especially in patients with CKD or those on potassium supplements 2, 3.
Pregnancy: Avoid losartan in pregnancy (all trimesters), as it causes serious fetal toxicity when given in the second and third trimesters 4.