What are the available tablet strengths of losartan and the typical adult starting dose for hypertension?

Losartan Tablet Strengths and Starting Dose for Hypertension

Losartan tablets are available in 25 mg, 50 mg, and 100 mg strengths, and the standard adult starting dose for hypertension is 50 mg once daily. 1

Available Formulations

Losartan is manufactured in the following tablet strengths:

• 25 mg (used primarily for patients with hepatic impairment or volume depletion) 1
• 50 mg (standard starting dose) 1
• 100 mg (maximum approved dose for hypertension) 1

Pediatric formulations include tablets at 12.5,25,50, and 100 mg, plus extemporaneous liquid preparations at 2 mg/mL. 2

Standard Adult Dosing for Hypertension

Initial Dose

• Start with 50 mg once daily for most adults with uncomplicated hypertension 1
• Start with 25 mg once daily in patients with possible intravascular volume depletion (e.g., those on diuretic therapy) or mild-to-moderate hepatic impairment 1

Dose Titration

• If blood pressure remains ≥140/90 mmHg after 2–4 weeks on 50 mg daily, increase to 100 mg once daily 3, 1
• The maximum FDA-approved dose for hypertension is 100 mg once daily 1
• Reassess blood pressure every 2–4 weeks during titration, aiming for a target of <130/80 mmHg within 3 months 3

Dosing Frequency

Losartan can be administered once daily or divided into twice-daily dosing (e.g., 50 mg twice daily for a total of 100 mg/day), though once-daily administration is more commonly recommended. 3, 4

Clinical Evidence on Optimal Dosing

The 50 mg dose produces near-maximal antihypertensive effects in most patients, with the 100 mg dose providing only modest additional blood pressure reduction. 5 However, for conditions beyond simple hypertension—such as heart failure with reduced ejection fraction or diabetic nephropathy—higher doses (100–150 mg daily) demonstrate superior cardiovascular and renal outcomes. 3, 6

The HEAAL trial showed that 150 mg daily was superior to 50 mg daily in heart failure patients, achieving a 10% relative risk reduction in death or hospitalization (P=0.027). 3 For diabetic nephropathy, the RENAAL trial established 100 mg once daily as the target dose, reducing the risk of doubling serum creatinine by 28% (P=0.002). 3, 4

Combination Therapy

If blood pressure remains uncontrolled on losartan 100 mg daily after 4–8 weeks, add hydrochlorothiazide 12.5–25 mg once daily rather than exceeding the maximum losartan dose. 3, 1 Fixed-dose combination products improve adherence and provide additive blood pressure lowering. 3

Monitoring Requirements

• Check serum creatinine/eGFR and potassium within 1–2 weeks after initiating losartan or increasing the dose, especially in patients with chronic kidney disease, diabetes, or those receiving potassium-sparing agents 3, 4
• Continue monitoring at least annually during maintenance therapy 3

Critical Safety Considerations

• Never combine losartan with ACE inhibitors or direct renin inhibitors (aliskiren), as dual RAAS blockade increases the risk of hyperkalemia, syncope, and acute kidney injury by 2–3-fold without cardiovascular benefit 3, 4
• Losartan is absolutely contraindicated in pregnancy due to serious fetal toxicity (renal dysfunction, oligohydramnios, skull hypoplasia, fetal death) 3
• Losartan can be taken without regard to food 7