For a 62-year-old patient on losartan 50 mg, what is the maximum daily dose and what add-on antihypertensive should be used if blood pressure remains uncontrolled?

Losartan Dosing and Add-On Therapy for Uncontrolled Hypertension

Increase losartan from 50 mg to 100 mg once daily first, then add hydrochlorothiazide 12.5–25 mg once daily if blood pressure remains ≥140/90 mmHg after 2–4 weeks on the maximum dose. 1, 2, 3

Maximum Dose of Losartan

• The FDA-approved maximum dose of losartan for hypertension is 100 mg once daily. 3
• This can be administered as a single 100 mg dose or split into 50 mg twice daily (total 100 mg/day). 1, 4
• Current guidelines recommend maximizing the first-line agent before adding additional medications. 2
• Reassess blood pressure after 2–4 weeks on the increased dose. 2

Important caveat: Before increasing the dose, verify medication adherence—non-adherence is a common cause of treatment failure. 2

Add-On Therapy Strategy

First Add-On: Thiazide or Thiazide-Like Diuretic

If blood pressure remains uncontrolled on losartan 100 mg daily after 2–4 weeks, add a thiazide or thiazide-like diuretic. 2

Preferred options include:

• Hydrochlorothiazide 12.5–25 mg once daily 1, 2, 3
• Indapamide 2.5 mg once daily 5, 2
• Chlorthalidone 12.5–25 mg once daily 2

The combination of an ARB with a thiazide diuretic provides additive blood pressure-lowering effects. 2 In one study, adding 12.5 mg hydrochlorothiazide to losartan 50 mg produced a placebo-adjusted reduction of approximately 15.5 mmHg systolic and 9.2 mmHg diastolic. 1

Clinical evidence: Combination therapy with losartan 50 mg plus hydrochlorothiazide 12.5 mg achieved better blood pressure control than losartan 100 mg monotherapy (33.2 vs 29.5 mmHg systolic reduction, p<0.05). 6

Second Add-On: Calcium Channel Blocker

If blood pressure remains uncontrolled on losartan 100 mg plus a thiazide diuretic, add a dihydropyridine calcium channel blocker such as amlodipine 5–10 mg once daily. 5, 2

This creates a three-drug regimen: ARB + thiazide diuretic + calcium channel blocker. 2

Third Add-On: Spironolactone for Resistant Hypertension

If blood pressure remains uncontrolled on three medications at optimal doses, add spironolactone 25–50 mg once daily if serum potassium <4.5 mmol/L and estimated GFR >45 mL/min. 2

Consider referral to a hypertension specialist if blood pressure remains ≥160/100 mmHg on ≥3 drugs or if multiple drug intolerances occur. 2

Target Blood Pressure Goals

• Aim for <130/80 mmHg in most adults with hypertension to reduce cardiovascular risk. 1, 2
• The European guidelines recommend a target of 120–129 mmHg systolic, provided treatment is well tolerated. 5
• Monitor blood pressure every 2–4 weeks after each medication adjustment until the target is reached. 1, 5, 2

Critical Safety Monitoring

Renal Function and Electrolytes

Monitor serum creatinine/eGFR and potassium within 1–2 weeks after initiating or increasing losartan dose, especially when adding a diuretic. 1, 2

• Watch for hyperkalemia risk, particularly in patients with chronic kidney disease or those on potassium supplements. 2
• Monitor for hypokalemia and hyponatremia when adding thiazide diuretics. 2

Absolute Contraindications

Never combine losartan with ACE inhibitors or direct renin inhibitors (aliskiren). 1, 2

Dual renin-angiotensin system blockade increases the risk of hyperkalemia, syncope, and acute kidney injury by 2–3-fold without added cardiovascular benefit. 1

Special Considerations for This 62-Year-Old Patient

• At age 62, standard adult dosing applies without age-related dose reduction. 1
• Consider fixed-dose combination pills (losartan/hydrochlorothiazide) to improve adherence. 5, 2
• Antihypertensive treatment should be maintained lifelong, even beyond age 85, if well tolerated. 5

Common Pitfalls to Avoid

• Do not rely solely on monotherapy dose escalation—combination therapy with agents from different classes yields better blood pressure control. 6
• Do not add a beta-blocker as second- or third-line therapy unless there are compelling indications (angina, post-MI, heart failure, atrial fibrillation), as beta-blockers are less effective than calcium channel blockers or diuretics for stroke prevention. 1
• Do not exceed 100 mg daily of losartan for hypertension—add a second agent instead. 1, 2, 3