Losartan Dosing for Hypertension
For adults with hypertension, start losartan at 50 mg once daily and titrate to 100 mg once daily after 2-4 weeks if blood pressure remains ≥140/90 mmHg, as this dose provides near-maximal antihypertensive effect and is supported by the most recent ESC guidelines. 1, 2
Initial Dosing and Titration
Begin with losartan 50 mg once daily as the standard starting dose for most adults with hypertension, which can be taken without regard to food and provides adequate 24-hour blood pressure control. 3, 4
Titrate to 100 mg once daily after 2-4 weeks if office blood pressure remains ≥140/90 mmHg or home readings remain ≥135/85 mmHg, as dose-ranging studies demonstrate that 50 mg produces near-maximum effects while 100 mg represents the maximum recommended daily dose. 2, 3, 4
Reassess blood pressure every 2-4 weeks during titration, aiming to achieve target blood pressure <130/80 mmHg within 3 months of initiating therapy. 1, 2
Consider combination therapy with hydrochlorothiazide 12.5-25 mg daily if blood pressure remains uncontrolled on losartan 100 mg alone, as fixed-dose combinations improve adherence and provide additive blood pressure-lowering effects. 1, 2
Special Population Adjustments
Elderly Patients (≥65 years)
No initial dose adjustment is necessary in elderly patients, as pharmacokinetic studies show no clinically significant age-related differences in losartan metabolism. 3, 4, 5
Titrate more gradually in very elderly (≥85 years) or frail patients, increasing doses every 2-4 weeks rather than weekly, with close monitoring for symptomatic hypotension and orthostatic changes. 1, 2, 6
Measure blood pressure in both sitting and standing positions due to increased risk of orthostatic hypotension in elderly patients, checking 1 and 3 minutes after standing. 1, 6
Renal Impairment
No dose adjustment required for patients with mild to moderate renal impairment (eGFR 30-90 mL/min/1.73 m²), including those on hemodialysis, as losartan is not removed during dialysis. 4, 7, 5
Start with standard 50 mg daily even in patients with moderate to severe renal insufficiency (eGFR 10-29 mL/min/1.73 m²), as clinical trials demonstrate effective blood pressure reduction without deterioration in renal function. 7
Monitor serum creatinine and potassium within 1-2 weeks after initiating therapy or dose changes, then at least annually during maintenance, as ARBs carry risk of hyperkalemia particularly in chronic kidney disease. 2, 6
Continue losartan even as eGFR declines below 30 mL/min/1.73 m² for cardiovascular benefit in patients with diabetic nephropathy, using a target dose of 100 mg daily. 2
Hepatic Impairment
Reduce starting dose to 25 mg once daily in patients with hepatic impairment, as losartan plasma concentrations increase approximately 5-fold due to decreased first-pass metabolism. 2, 4
Titrate cautiously in 2-4 week intervals based on blood pressure response and tolerability in patients with liver disease. 2
Pregnancy Contraindication
Losartan is absolutely contraindicated during pregnancy (all trimesters) due to serious fetal toxicity including renal dysfunction, oligohydramnios, skull hypoplasia, and fetal death. 1, 2, 4
Discontinue immediately upon pregnancy recognition and switch to pregnancy-safe alternatives such as methyldopa, labetalol, or extended-release nifedipine. 1
Counsel women of childbearing potential about contraception requirements before initiating losartan therapy. 2
Critical Safety Considerations
Never combine losartan with ACE inhibitors or direct renin inhibitors (aliskiren), as dual RAS blockade increases risks of hyperkalemia, syncope, and acute kidney injury by 2-3 fold without providing additional cardiovascular benefit. 1, 2, 6
Avoid potassium supplements and potassium-sparing diuretics unless specifically indicated and closely monitored, as ARBs inherently increase serum potassium. 2
Monitor for hyperkalemia (>6 mEq/L) particularly in patients with diabetes, chronic kidney disease, or those receiving NSAIDs, checking levels within 1-2 weeks of initiation or dose changes. 2, 7
Dosing Frequency Options
Once-daily dosing is preferred for the full 100 mg dose to maximize adherence and provide consistent 24-hour blood pressure control without affecting circadian rhythm. 2, 3, 4
Twice-daily dosing (50 mg BID) is acceptable if more consistent coverage is desired, as ACC/AHA guidelines list losartan's frequency as "1 or 2" times daily for the 50-100 mg total daily dose range. 2
Common Pitfalls to Avoid
Do not underdose: Clinical practice data show less than 25% of patients are titrated to target doses of 100 mg, yet higher doses provide significantly greater cardiovascular benefits than 50 mg daily. 2, 8
Do not delay full-dose therapy in patients with grade 2 hypertension (≥160/100 mmHg); consider starting with two agents (losartan plus hydrochlorothiazide or calcium channel blocker) from the outset. 2
Do not assume medication intolerance without direct questioning; patients often discontinue therapy due to cost, access issues, or misunderstanding rather than true adverse effects. 2
Do not prematurely discontinue for mild hyperkalemia (5.5-6.0 mEq/L); implement potassium-lowering strategies (dietary restriction, diuretic adjustment, potassium binders) before stopping the medication. 2