What is the recommended dosage and usage of Losartan (angiotensin II receptor blocker) for treating hypertension?

Losartan Dosing and Usage for Hypertension

For adults with hypertension, start losartan at 50 mg once daily and titrate up to 100 mg once daily as needed for blood pressure control, with a lower starting dose of 25 mg recommended only in patients with possible intravascular depletion (such as those on diuretics). 1

Standard Adult Dosing

• Initial dose: 50 mg once daily is the standard starting point for most hypertensive patients 1
• Maximum dose: 100 mg once daily provides optimal blood pressure reduction 1
• Reduced starting dose: 25 mg once daily should be used in patients with possible intravascular volume depletion, particularly those already on diuretic therapy 1

Clinical trials demonstrate that doses of 50-100 mg once daily produce statistically significant systolic/diastolic blood pressure reductions in the range of 5.5-10.5/3.5-7.5 mmHg compared to placebo, with the 150 mg dose providing no additional benefit over 50-100 mg 1. Lower doses (10-25 mg) produce inconsistent trough responses and are inadequate for most patients 1.

Dosing for Specific Indications

Hypertension with Left Ventricular Hypertrophy

• Start with losartan 50 mg once daily 1
• Add hydrochlorothiazide 12.5 mg daily and/or increase losartan to 100 mg once daily based on blood pressure response 1
• Further titrate hydrochlorothiazide to 25 mg daily if needed for blood pressure control 1

This approach is supported by the LIFE trial, which demonstrated that losartan-based therapy reduced cardiovascular events by 13% and stroke by 25% compared to atenolol in patients with hypertension and left ventricular hypertrophy 2, 3. The combination of losartan with hydrochlorothiazide provides additive blood pressure reduction of 15.5/9.2 mmHg compared to placebo 1.

Nephropathy in Type 2 Diabetes

• Start with 50 mg once daily 1
• Increase to 100 mg once daily based on blood pressure response 1

Blockers of the renin-angiotensin system should be a regular component of treatment in diabetic patients with hypertension, as they provide additional renal protection beyond blood pressure lowering alone 2.

Pediatric Dosing (Ages 6-16 Years)

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

Pediatric trials showed dose-dependent blood pressure reductions, with higher doses (25-50 mg in patients <50 kg; 50-100 mg in patients ≥50 kg) reducing diastolic blood pressure by 5-6 mmHg more than the lowest doses 1.

Special Populations

Hepatic Impairment

• Start with 25 mg once daily in patients with mild-to-moderate hepatic impairment 1
• Not studied in severe hepatic impairment; use with extreme caution 1

Elderly Patients

• Standard dosing applies, but initial doses and titration should be more gradual due to increased risk of adverse effects, particularly in very old and frail patients 2
• Blood pressure should be measured in both sitting and standing positions due to increased risk of postural hypotension 2

Dosing Frequency Considerations

Once-daily dosing is standard, but twice-daily dosing at 50-100 mg/day total provides consistently larger trough responses than once-daily dosing at the same total dose 1. The trough-to-peak ratio for systolic and diastolic responses ranges from 50-95% and 60-90%, respectively, indicating sustained 24-hour blood pressure control with once-daily dosing 1.

Combination Therapy

Addition of hydrochlorothiazide 12.5 mg to losartan 50 mg once daily results in placebo-adjusted blood pressure reductions of 15.5/9.2 mmHg 1. This combination is particularly effective in patients requiring more aggressive blood pressure control and is well-tolerated with an adverse effect profile similar to losartan monotherapy 4.

Important Clinical Considerations

Higher doses provide greater cardiovascular benefit: The HEAAL trial demonstrated that losartan 150 mg daily was superior to 50 mg daily for heart failure outcomes, with a 10% relative risk reduction in death or hospitalization 3. However, for hypertension specifically, doses above 100 mg daily have not shown additional blood pressure-lowering benefit 1.

Race-based response differences: Losartan is effective across all racial groups, though the effect is somewhat less pronounced in Black patients (typically a low-renin population) 1. The LIFE study benefits were not observed in the Black patient subgroup 5.

First-dose hypotension risk is low with losartan compared to ACE inhibitors, and no dosage adjustment is required in elderly patients or those with mild-to-moderate renal dysfunction 6.