Should I switch an elderly female patient with hypertension and proteinuria (albumin-to-creatinine ratio of 45) from Amlodipine (Norvasc) to Losartan (an angiotensin II receptor blocker) 25mg?

Should You Switch from Amlodipine to Losartan in This Elderly Hypertensive Patient with Proteinuria?

Yes, you should add or switch to losartan (or another RAAS blocker) in this patient with proteinuria (albumin-to-creatinine ratio of 45 mg/g), as renin-angiotensin system blockers are specifically recommended for patients with proteinuria due to their blood pressure-independent antiproteinuric effects. 1, 2

Rationale for RAAS Blocker Therapy in Proteinuria

The presence of proteinuria (albumin-to-creatinine ratio ≥30 mg/g) is a compelling indication for RAAS blockade with either an ACE inhibitor or ARB, regardless of whether the patient has diabetes. 1 Multiple guidelines consistently recommend:

• Blockers of the renin-angiotensin system should be a regular component of treatment when microalbuminuria or proteinuria is present, even when blood pressure is in the high-normal range. 1
• ACE inhibitors and ARBs have a pronounced antiproteinuric effect and their use should be preferred in patients with proteinuria. 1
• For proteinuria >1 g/day (or albumin-to-creatinine ratio >1000 mg/g), start ACE inhibitor or ARB treatment with uptitration depending on blood pressure response. 2

Your patient's albumin-to-creatinine ratio of 45 mg/g indicates microalbuminuria (30-300 mg/g range), which warrants RAAS blocker therapy.

Evidence Supporting Losartan Over Amlodipine for Proteinuria

Direct comparative trials demonstrate that losartan significantly reduces proteinuria while amlodipine does not, despite achieving similar blood pressure control:

• In the JLIGHT study, losartan reduced 24-hour urinary protein excretion by 20.7% at 3 months, 35.2% at 6 months, and 35.8% at 12 months, whereas amlodipine showed no significant change in proteinuria throughout the 12-month period, despite equivalent blood pressure reduction. 3
• Another randomized trial in non-diabetic proteinuric renal disease showed losartan decreased proteinuria by 32.4% at 4 weeks and 50.4% at 20 weeks, while amlodipine produced no significant proteinuria changes, despite similar blood pressure control. 4
• The antiproteinuric effect of losartan was evident even in patients who did not achieve goal blood pressure, indicating a blood pressure-independent renoprotective mechanism. 5, 3

Practical Implementation Strategy

Option 1: Add Losartan to Current Regimen (Preferred Initial Approach)

• Start losartan 25 mg daily while continuing amlodipine 10 mg and metoprolol 25 mg. 6
• This approach maintains blood pressure control while adding renoprotection. 1, 7
• Monitor serum creatinine, potassium, and blood pressure within 2-4 weeks of initiation. 6
• A temporary increase in serum creatinine up to 30% is acceptable and not a reason to discontinue therapy. 2, 6

Option 2: Switch from Amlodipine to Losartan

• If you prefer monotherapy simplification or if blood pressure is well-controlled, you can discontinue amlodipine and start losartan 50 mg daily. 6
• However, given her current BP of 160/75 mmHg (above goal), adding losartan is more appropriate than switching. 1

Dose Titration Plan

• If proteinuria reduction is inadequate after 4-8 weeks and the medication is well tolerated, uptitrate losartan to 50 mg daily (if started at 25 mg) or 100 mg daily (if started at 50 mg). 6
• Target blood pressure should be <130/80 mmHg in patients with proteinuria. 1, 6
• Titrate losartan upward as far as tolerated to achieve proteinuria reduction, ideally to albumin-to-creatinine ratio <30 mg/g. 2

Important Monitoring and Safety Considerations

Laboratory Monitoring

• Check serum creatinine, eGFR, and potassium levels within 2-4 weeks of initiation and after each dose increase. 6
• Recheck albumin-to-creatinine ratio at 3 months to assess antiproteinuric response. 2

When to Hold or Discontinue Losartan

• Instruct the patient to temporarily hold losartan during periods of volume depletion (acute illness with vomiting/diarrhea, excessive diuresis). 2, 6
• Consider reducing dose or discontinuing if serum creatinine rises by more than 30% within 4 weeks of initiation, or if uncontrolled hyperkalemia (K+ >5.5 mEq/L) or symptomatic hypotension occurs. 6
• Do not stop losartan with modest and stable increase in serum creatinine (up to 30%) unless kidney function continues to worsen. 2

Special Considerations for Elderly Patients

In elderly patients, initial doses should be more gradual due to increased risk of adverse effects, but there is no age-based contraindication to RAAS blocker therapy. 1

• Losartan 25 mg daily is an appropriate starting dose in elderly patients. 6
• Measure blood pressure in both sitting and standing positions to detect orthostatic hypotension, which is more common in elderly patients. 1, 8
• Calcium channel blockers like amlodipine have minimal association with orthostatic hypotension, while alpha-blockers have high risk; ACE inhibitors and ARBs have low risk. 8

Adjunctive Measures to Enhance Antiproteinuric Effect

• Restrict dietary sodium to <2.0 g/day (<90 mmol/day) to enhance the antiproteinuric effect of losartan. 2, 6
• Normalize weight through appropriate diet and exercise to reduce proteinuria. 2

Common Pitfalls to Avoid

• Do not withhold RAAS blocker therapy simply because the patient is elderly or normotensive—proteinuria itself is the indication. 1, 9
• Do not discontinue losartan for modest creatinine increases (<30% from baseline) that stabilize, as this is an expected hemodynamic effect. 2, 6
• Do not assume that blood pressure control alone is sufficient in proteinuric patients—RAAS blockade provides additional renoprotection independent of blood pressure lowering. 5, 4, 3