What is the recommended starting dose for losartan (angiotensin II receptor antagonist)?

Starting Dose for Losartan

The recommended starting dose for losartan is 50 mg once daily for adult hypertension, though a lower starting dose of 25 mg is recommended for patients with possible intravascular depletion (e.g., those on diuretic therapy). 1

Dosing Guidelines Based on Clinical Context

For Hypertension:

• Standard starting dose: 50 mg once daily 1
• Maximum dose: Can be increased to 100 mg once daily as needed 1
• Special populations requiring lower starting dose (25 mg):
  • Patients with possible volume depletion (e.g., on diuretics) 1
  • Patients with mild-to-moderate hepatic impairment 1

For Heart Failure with Reduced Ejection Fraction (HFrEF):

• Starting dose: 25-50 mg once daily 2
• Target dose: 50-150 mg once daily 2
  • ACC/AHA guidelines recommend a target dose of up to 150 mg daily 2
  • FDA-approved labeling has 100 mg as the maximal dose 2

For Hypertensive Patients with Left Ventricular Hypertrophy:

• Starting dose: 50 mg once daily 1
• Titration: Can be increased to 100 mg once daily based on blood pressure response 1

For Nephropathy in Type 2 Diabetic Patients:

• Starting dose: 50 mg once daily 1
• Target dose: 100 mg once daily 1

Titration and Optimization

When initiating losartan therapy, follow these principles:

• Adjust dosage according to blood pressure response 1
• Titrate medication no more frequently than every 2 weeks to target doses or maximally tolerated doses 2
• For HFrEF patients, aim to achieve at least 50% of the target dose (50 mg for losartan) 2

Important Clinical Considerations

Efficacy

• Losartan has similar efficacy to ACE inhibitors in reducing blood pressure in mild to moderate hypertension 3
• In HFrEF, higher doses (150 mg daily) have shown greater benefit than lower doses (50 mg daily) in reducing death or heart failure hospitalization 2

Safety and Tolerability

• Losartan is generally well-tolerated with dizziness being the most commonly reported adverse effect 3, 4
• First-dose hypotension is uncommon, possibly due to its slower onset of action 5
• Unlike ACE inhibitors, losartan has a lower incidence of cough 4

Contraindications and Cautions

• Avoid in pregnancy (Class III: Harm) 1
• Use with caution in patients with severe bilateral renal artery stenosis 2
• Not recommended in patients with severe hepatic impairment 1
• Routine combined use of an ACE inhibitor, ARB, and aldosterone antagonist is potentially harmful for patients with HFrEF (Class III: Harm) 2

Monitoring

• Monitor blood pressure response
• For patients with HFrEF, assess for signs and symptoms of heart failure
• In patients with renal impairment or those taking potassium-sparing medications, monitor potassium levels

By following these evidence-based guidelines for losartan dosing, you can optimize efficacy while minimizing adverse effects in various clinical scenarios.