Losartan Prescribing Considerations
Losartan should be initiated at 50 mg once daily for hypertension, with titration to 100 mg daily for maximum efficacy, particularly in patients with heart failure, left ventricular hypertrophy, or diabetic nephropathy. 1, 2
Dosing Recommendations
Initial Dosing
- Standard starting dose: 50 mg once daily 1
- Reduced starting dose (25 mg daily) recommended for:
Dose Titration
- Increase to maximum dose of 100 mg once daily based on blood pressure response 1
- For heart failure patients, titrate to target dose or maximally tolerated dose no more frequently than every 2 weeks 2
- For diabetic nephropathy, increase to 100 mg once daily for optimal renoprotection 1
Specific Clinical Indications
Hypertension
- Indicated for adults and children ≥6 years old to lower blood pressure 1
- Target dose of 100 mg daily provides greater blood pressure reduction than 50 mg 3
- May be administered with other antihypertensive agents 1
- Can be given without regard to food 4
Heart Failure with Reduced Ejection Fraction (HFrEF)
- For patients with HFrEF, aim for at least 50% of target dose (50 mg daily) 2
- Higher doses (100 mg daily) provide greater reduction in mortality and heart failure hospitalization 3
Left Ventricular Hypertrophy
- Starting dose of 50 mg once daily 1
- Consider adding hydrochlorothiazide 12.5 mg daily and/or increasing losartan to 100 mg daily based on blood pressure response 1
- Note: Benefit may not apply to Black patients 1
Diabetic Nephropathy
- Indicated for type 2 diabetic patients with elevated serum creatinine and proteinuria 1
- Start with 50 mg once daily and increase to 100 mg once daily 1
- Reduces progression to end-stage renal disease or doubling of serum creatinine 1
Special Populations
Hepatic Impairment
- Reduced starting dose (25 mg daily) for mild-to-moderate hepatic impairment 1
- Not studied in severe hepatic impairment - avoid use 1
Renal Impairment
- No dosage adjustment necessary for various degrees of renal insufficiency 4
- Not removed during hemodialysis 4
Pediatric Patients
- Recommended for children ≥6 years with hypertension 1
- Starting dose: 0.7 mg/kg once daily (up to 50 mg total) 1
- Not recommended for children <6 years or with eGFR <30 mL/min/1.73m² 1
Elderly Patients
Combination Therapy
For Inadequate Response to Monotherapy
- Add a calcium channel blocker (e.g., amlodipine) as next agent 3
- Alternative: add a thiazide/thiazide-like diuretic (e.g., hydrochlorothiazide 12.5-25 mg daily) 3
- For resistant hypertension, consider triple therapy with ARB + CCB + thiazide diuretic 3
For Left Ventricular Hypertrophy
- Consider combination with hydrochlorothiazide (12.5-25 mg) 1
Monitoring and Follow-up
Initial Follow-up
- For stage 1 hypertension with 10-year ASCVD risk ≥10%: Recheck BP in 1 month 2
- For stage 2 hypertension: Evaluate within 1 month of diagnosis 2
- Monitor serum potassium and creatinine periodically 2
Contraindications and Precautions
Absolute Contraindications
- Pregnancy (contraindicated in 2nd and 3rd trimesters) 4
- History of angioedema with ARBs 2
- Simultaneous use with ACE inhibitors or direct renin inhibitors 2
Adverse Effects
- Generally well-tolerated with adverse event profile similar to placebo 5, 6
- Risk of hyperkalemia, especially in patients with CKD or those on potassium supplements 2
- Risk of acute renal failure in patients with severe bilateral renal artery stenosis 2
Clinical Pearls
- Losartan has a favorable drug-drug interaction profile 4
- No significant interactions with hydrochlorothiazide, warfarin, or digoxin 4
- Metabolized primarily by CYP3A4, 2C9, and 2C10 isoenzymes 4
- Pharmacokinetics are linear and dose-proportional 4
- Some evidence suggests 100 mg daily may provide optimal clinical benefits compared to 50 mg 7