How can I improve my impaired renal function with a glomerular filtration rate (GFR) of 50%, hypertension, and current medication regimen of Losartan (angiotensin II receptor blocker) 100mg and hydrochlorothiazide (diuretic) 25mg daily, without diabetes?

Optimizing Kidney Function with Stage 3 CKD and Hypertension

You are already on the correct foundation therapy with Losartan (an ARB), but your current regimen needs optimization: maximize your Losartan dose to 100mg daily, achieve stricter blood pressure control targeting <120 mmHg systolic, restrict dietary sodium to less than 2 grams per day, and consider adding an SGLT2 inhibitor if you have any proteinuria. 1

Blood Pressure Control Strategy

Target Blood Pressure

• Your systolic blood pressure goal should be <120 mmHg using standardized office measurement, which provides the greatest protection against kidney disease progression and cardiovascular events 2, 1
• This aggressive target is supported by the most recent guidelines, though it requires careful monitoring 1
• Achieving this target typically requires 3-4 antihypertensive medications, not just 1-2 2

Optimize Your Current Medications

Losartan Dose Adjustment:

• Increase your Losartan from 100mg to the maximum dose if not already there, as uptitrating to maximally tolerated doses provides superior kidney protection 2
• ARBs like Losartan lower intraglomerular pressure independent of systemic blood pressure, which directly protects kidney function 2
• Do not stop Losartan if your creatinine increases up to 30% - this reflects beneficial hemodynamic changes, not kidney damage 2, 1
• Monitor your creatinine and potassium within 7-14 days after any dose adjustment 1

Hydrochlorothiazide Consideration:

• At your GFR level (50%, approximately 30-45 mL/min), thiazide diuretics become less effective 2
• Consider switching from hydrochlorothiazide to a loop diuretic (like furosemide) for better efficacy at your kidney function level 2
• Alternatively, chlorthalidone or indapamide are preferred thiazide-like diuretics if continuing this class 1

Critical Lifestyle Modifications

Dietary Sodium Restriction:

• Restrict sodium intake to less than 2 grams per day (<90 mmol/day) - this is the single most important dietary intervention 2, 1
• Sodium restriction enhances the effectiveness of your blood pressure medications and directly reduces proteinuria 2, 1
• This requires reading food labels carefully and avoiding processed foods 2

Additional Lifestyle Measures:

• Achieve and maintain normal body weight (BMI <25) if currently overweight 2, 1
• Stop smoking immediately if you smoke, as it accelerates kidney function decline 2
• Exercise regularly - at least 150 minutes per week of moderate-intensity activity 1

Additional Kidney-Protective Medications

Check for Proteinuria:

• Request a urine albumin-to-creatinine ratio test if not recently done 2
• If you have any proteinuria (>30 mg/g), additional protective medications are indicated 2

SGLT2 Inhibitors (Even Without Diabetes):

• Consider adding an SGLT2 inhibitor (like empagliflozin or dapagliflozin) as these provide kidney protection independent of diabetes status 2
• These can be initiated at your GFR level and continued until dialysis 2
• They slow kidney disease progression and reduce cardiovascular events 2

Mineralocorticoid Receptor Antagonists:

• If proteinuria persists despite optimized therapy, a nonsteroidal mineralocorticoid receptor antagonist (like finerenone) can be added 2
• This requires careful potassium monitoring given your kidney function 2
• Traditional spironolactone may be used for resistant hypertension but requires even closer potassium monitoring 2, 1

Monitoring Strategy

Regular Laboratory Monitoring:

• Check creatinine and potassium within 1-2 weeks after any medication change 1
• Monitor these labs every 3-6 months when stable 2
• Expect and tolerate up to 30% creatinine increase after starting or increasing ARB dose - this is protective, not harmful 2, 1
• Discontinue or reduce ARB only if creatinine rises >30% or if hyperkalemia (>6 mEq/L) develops 2

Blood Pressure Monitoring:

• Monitor blood pressure regularly at home to ensure targets are met 1
• Use standardized measurement technique for accuracy 2

Important Caveats

Volume Depletion Risk:

• Hold your Losartan and diuretic during illness with vomiting, diarrhea, or poor oral intake to prevent acute kidney injury 2
• Diuretic-induced volume depletion is the most common preventable cause of creatinine elevation with ARBs 2

Hyperkalemia Management:

• If potassium becomes elevated, use potassium-wasting diuretics or potassium binders to allow continuation of kidney-protective ARB therapy 2
• Do not automatically stop Losartan for mild potassium elevations - adjust other factors first 2

Medication Timing:

• Your current dose of 100mg Losartan daily is appropriate, but ensure it's truly 100mg total (not 2 x 50mg if that exceeds recommended dosing) 3
• The FDA-approved maximum is 100mg daily for hypertension 3

What Will NOT Improve Your Kidney Function

• Simply continuing your current regimen without optimization will not slow progression 2
• Achieving only 140/90 mmHg is insufficient - you need more aggressive control 1
• Single or dual therapy is inadequate for your blood pressure goals 2

The evidence strongly supports that aggressive blood pressure control with maximized ARB therapy, strict sodium restriction, and consideration of additional kidney-protective agents offers your best chance of slowing kidney disease progression and reducing cardiovascular risk. 2, 1