How should I treat a patient with hypertension already on losartan (angiotensin II receptor antagonist) 50 mg?

Treatment of Hypertension in a Patient on Losartan 50 mg

Increase losartan to 100 mg once daily and reassess blood pressure in 2-4 weeks; if BP remains uncontrolled, add a thiazide diuretic such as hydrochlorothiazide 12.5 mg or indapamide 2.5 mg daily. 1, 2

Step 1: Maximize Current ARB Therapy

• First, increase losartan from 50 mg to 100 mg once daily before adding additional medications, as current guidelines recommend maximizing the first-line agent 1
• The FDA-approved dosing for losartan allows titration up to 100 mg once daily for hypertension, which is the maximum recommended dose 2
• Reassess blood pressure after 2-4 weeks on the increased dose 1
• Before increasing the dose, verify medication adherence, as non-adherence is a common cause of treatment failure 1

Step 2: Add Thiazide Diuretic if Needed

If blood pressure remains uncontrolled after 2-4 weeks on losartan 100 mg daily:

• Add a thiazide or thiazide-like diuretic as the next step 1, 3
• Preferred options include:
  • Hydrochlorothiazide 12.5-25 mg once daily 4, 2
  • Indapamide 2.5 mg once daily 1, 3
  • Chlorthalidone 12.5-25 mg once daily (preferred due to longer half-life and proven cardiovascular benefit) 4
• The combination of an ARB with a thiazide diuretic provides additive blood pressure-lowering effects 4, 5

Step 3: Further Intensification if Needed

If BP remains uncontrolled on losartan 100 mg plus thiazide diuretic:

• Add a calcium channel blocker (dihydropyridine) such as amlodipine 5-10 mg once daily 4, 3
• This creates a three-drug regimen: ARB + thiazide diuretic + calcium channel blocker 3
• Consider fixed-dose combination pills to improve adherence 3

Step 4: Resistant Hypertension Management

If BP 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 4
• Consider referral to a hypertension specialist if BP remains ≥160/100 mmHg on ≥3 drugs or if multiple drug intolerances occur 4

Target Blood Pressure Goals

• Aim for BP <130/80 mmHg in most adults with hypertension to reduce cardiovascular risk 4, 1
• For patients with specific conditions (e.g., diabetes, chronic kidney disease), the same target applies 4

Important Monitoring and Safety Considerations

• Monitor serum potassium and creatinine within 1-2 weeks after initiating or increasing losartan dose, especially when adding a diuretic 4, 6
• Avoid combining losartan with ACE inhibitors, as this increases risk of hyperkalemia and renal dysfunction without additional benefit 4, 6
• Watch for hyperkalemia risk, particularly in patients with chronic kidney disease or those on potassium supplements 4
• Monitor for hypokalemia and hyponatremia when adding thiazide diuretics 4

Common Pitfalls to Avoid

• Do not add a second medication before maximizing the first agent - this is a common error that leads to polypharmacy without optimal dosing 1
• Do not use ACE inhibitor + ARB combinations - this practice is contraindicated due to increased adverse effects without mortality benefit 4, 6
• Do not undertitrate - less than 25% of patients are titrated to target doses in clinical practice, leading to suboptimal outcomes 6