What losartan dose should be added to amlodipine 2.5 mg daily for hypertension?

Losartan Dosing to Complement Amlodipine 2.5 mg for 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. 1, 2

Initial Dosing Strategy

• Begin with losartan 50 mg once daily as the standard starting dose for hypertension when adding to amlodipine 2.5 mg. 1, 2
• The 50 mg starting dose is appropriate regardless of the concurrent low-dose amlodipine, as this represents the FDA-approved initial dose for essential hypertension. 2
• Administer losartan at any convenient time of day to promote adherence; it can be taken with or without food. 1, 3

Titration to Target Dose

• Increase to losartan 100 mg once daily after 2–4 weeks if office blood pressure remains ≥140/90 mmHg or home readings stay ≥135/85 mmHg. 1, 2
• The maximum FDA-approved dose for hypertension is 100 mg daily, which can be given as a single dose or split into 50 mg twice daily for more consistent 24-hour coverage. 1, 2, 3
• Reassess blood pressure every 2–4 weeks during titration, aiming for a target of <130/80 mmHg within 3 months of therapy initiation. 1

Monitoring Requirements

• Check serum creatinine/eGFR and potassium within 1–2 weeks after starting losartan or increasing the dose, especially if the patient has diabetes, chronic kidney disease, or is taking potassium-sparing agents. 1
• Monitor blood pressure in both sitting and standing positions in elderly patients (≥65 years) to detect orthostatic hypotension. 1
• Continue monitoring at least annually during maintenance therapy once blood pressure is controlled. 1

If Blood Pressure Remains Uncontrolled

After 4–8 Weeks on Losartan 100 mg + Amlodipine 2.5 mg:

• First, increase amlodipine from 2.5 mg to 5 mg daily before adding a third agent, as 2.5 mg is a subtherapeutic dose and the standard starting dose is 5 mg. 1
• If blood pressure remains ≥140/90 mmHg on losartan 100 mg + amlodipine 5–10 mg, add hydrochlorothiazide 12.5–25 mg once daily to create triple therapy (ARB + CCB + thiazide diuretic). 1
• Prefer single-pill fixed-dose combinations when available (e.g., losartan/hydrochlorothiazide) to markedly improve adherence. 1

For Resistant Hypertension (Uncontrolled on Triple Therapy):

• Add spironolactone 25 mg daily as the fourth agent; it is the most effective add-on in resistant hypertension. 1

Critical Safety Considerations

• Never combine losartan with an ACE inhibitor or direct renin inhibitor (aliskiren); dual RAAS blockade increases the risk of hyperkalemia, syncope, and acute kidney injury by 2–3-fold without cardiovascular benefit. 1, 2
• Losartan is absolutely contraindicated in pregnancy due to serious fetal toxicity (renal dysfunction, oligohydramnios, skull hypoplasia, fetal death); discontinue immediately if pregnancy is detected. 1, 2
• Monitor for hyperkalemia, especially when combined with potassium supplements, potassium-sparing diuretics, or NSAIDs. 1

Special Population Adjustments

• Hepatic impairment (mild-to-moderate): Start at 25 mg once daily due to 5-fold higher plasma concentrations. 1, 2
• Elderly or frail patients (≥75 years): Initiate at the standard 50 mg dose but titrate more gradually (every 2–4 weeks rather than weekly) and monitor closely for dizziness, falls, and symptomatic hypotension. 1
• Volume depletion (e.g., on diuretics): Consider starting at 25 mg once daily to reduce hypotension risk. 2

Common Pitfalls to Avoid

• Do not leave amlodipine at 2.5 mg indefinitely; this is a subtherapeutic dose and should be increased to at least 5 mg (the standard starting dose) before adding multiple additional agents. 1
• Do not add a beta-blocker as second- or third-line therapy unless there is a compelling indication (heart failure, post-MI, angina, atrial fibrillation), as beta-blockers are less effective than CCBs or diuretics for stroke prevention. 1
• Confirm medication adherence through direct questioning before escalating therapy, as non-adherence is the most common cause of apparent treatment failure. 1
• Do not stop losartan prematurely for mild creatinine elevations (0.1–0.3 mg/dL increase); this reflects expected hemodynamic changes rather than tubular injury unless urinalysis shows acute tubular necrosis. 1