What is the best course of action for managing elevated blood pressure in a 45-year-old patient with a history of hypertension, currently taking Losartan 50mg (Angiotensin II receptor blocker) once daily, with recent elevated blood pressure readings and previous well-controlled blood pressure on the current medication regimen?

Management of Elevated Blood Pressure in a Patient on Losartan 50mg

Increase losartan to 100mg once daily and add hydrochlorothiazide 12.5-25mg as the next step for this patient with uncontrolled hypertension on current monotherapy.

Immediate Assessment and Confirmation

• Confirm true hypertension with out-of-office monitoring before intensifying therapy, as a single elevated reading (153/92 mmHg) after previous good control (118/65 mmHg) may represent white coat effect or situational elevation 1.
• Home BP ≥135/85 mmHg or 24-hour ambulatory BP ≥130/80 mmHg would confirm true hypertension requiring treatment adjustment 1, 2.
• Assess medication adherence first, as non-adherence is the most common cause of apparent treatment resistance—the patient reports only 1 tablet remaining, suggesting possible missed doses 3.
• Evaluate contributing factors including sleep difficulties (mentioned in history), which may indicate obstructive sleep apnea as a secondary cause of hypertension 1, 2.

Pharmacological Treatment Algorithm

Step 1: Optimize Current Losartan Dose

• Increase losartan from 50mg to 100mg once daily as the initial step, since the FDA-approved dosing allows up to 100mg daily for blood pressure control 4.
• The HEAAL trial demonstrated that losartan 150mg daily was superior to 50mg daily, and the ELITE II and OPTIMAAL trials support using higher doses of renin-angiotensin system blockers for optimal benefit 1.
• For hypertension management specifically, 100mg is the maximum recommended dose, with dose titration showing improved BP control 4, 5.

Step 2: Add Hydrochlorothiazide if Needed

• If BP remains ≥140/90 mmHg after 2-4 weeks on losartan 100mg, add hydrochlorothiazide 12.5-25mg once daily to create guideline-recommended combination therapy 1, 4.
• The 2024 ESC guidelines specifically recommend combination BP-lowering treatment as initial therapy for most patients with confirmed hypertension (BP ≥140/90 mmHg), with preferred combinations being a RAS blocker with either a dihydropyridine CCB or diuretic 1.
• Fixed-dose single-pill combination treatment (losartan/HCTZ) is recommended to improve adherence 1, 6.

Step 3: Consider Three-Drug Combination if Uncontrolled

• If BP remains uncontrolled on losartan 100mg plus HCTZ 25mg, add amlodipine 5-10mg daily to achieve the guideline-recommended triple therapy of RAS blocker + diuretic + calcium channel blocker 1, 3.
• This three-drug combination targets complementary mechanisms: renin-angiotensin system blockade, volume reduction, and vasodilation 3.

Blood Pressure Targets

• Target systolic BP of 120-129 mmHg if well tolerated, with a minimum acceptable target of <140/90 mmHg 1.
• Reassess BP within 2-4 weeks after any medication adjustment, with the goal of achieving target BP within 3 months 1, 3, 2.

Monitoring Parameters

• Check serum potassium and creatinine 2-4 weeks after dose adjustment, particularly when increasing losartan or adding HCTZ, to monitor for hyperkalemia (with ARB) or hypokalemia (with thiazide) 3.
• Monitor for specific adverse effects: dizziness with losartan dose increase, hypokalemia and hyperuricemia with HCTZ 3, 7.
• The patient's previous leg swelling with lisinopril should not recur with losartan, as this was the reason for the switch 7, 8.

Critical Pitfalls to Avoid

• Do not add a second RAS blocker (ACE inhibitor with the ARB), as combining two RAS blockers increases adverse events without additional cardiovascular benefit 1, 3.
• Do not delay treatment intensification for prolonged lifestyle modification alone when BP is ≥140/90 mmHg, as concurrent pharmacological therapy is recommended 1, 2.
• Do not assume treatment failure without first confirming medication adherence and ruling out secondary causes (sleep apnea given sleep difficulties, primary aldosteronism, renal artery stenosis) 3, 2.
• Do not add a third drug class before optimizing doses of the current regimen—this violates guideline-recommended stepwise approaches 3.

Lifestyle Modifications to Reinforce

• Sodium restriction to <2g/day provides the greatest BP reduction and is particularly important when adding a diuretic 1, 2.
• Weight management through the patient's current intermittent fasting approach should be encouraged, targeting BMI 20-25 kg/m² 3.
• Regular aerobic exercise and alcohol limitation to <100g/week provide additive BP reductions of 10-20 mmHg 3.

Timing and Follow-up

• Medications should be taken at the same time each day at the most convenient time for the patient to establish habitual adherence—the patient currently takes losartan at night (nocte), which is acceptable 1.
• Schedule follow-up in 2-4 weeks after dose adjustment to assess BP response and check electrolytes 3, 2.
• Provide medication refill for losartan 100mg (or losartan/HCTZ combination if moving directly to dual therapy) with appropriate quantity to ensure adherence 4.