Should a 34-year-old Black male with systemic lupus erythematosus (SLE), hypertension, and chronic kidney disease (CKD) continue taking losartan (angiotensin receptor blocker (ARB)) 100 mg daily despite having stable blood pressure readings and mildly elevated serum potassium levels?

Management of ARB Therapy in CKD with Severely Increased Albuminuria

Continue losartan 100 mg daily because it will reduce the progression of kidney disease and major adverse cardiovascular outcomes. 1

Assessment of Current Clinical Status

JB is a 34-year-old Black male with:

• Systemic lupus erythematosus
• Hypertension (well-controlled)
• Chronic kidney disease with severely increased albuminuria (>300 mg/g)
• Current BP readings: 122/82 mmHg (and previous readings of 129/78 mmHg, 127/76 mmHg)
• Serum potassium: 4.9 mmol/L (upper end of normal range)
• Serum creatinine: 1.8 mg/dL

Rationale for Continuing Losartan

Albuminuria Reduction Benefits

• The 2024 KDIGO guidelines strongly recommend (1B) starting renin-angiotensin system inhibitors (RASi) such as ARBs for people with CKD and severely increased albuminuria (G1-G4, A3) without diabetes 1
• JB's urine albumin-creatinine ratio is >300 mg/g, placing him in the severely increased albuminuria category (A3)
• ARBs significantly reduce the risk of CKD progression, as measured by doubling of serum creatinine or progression to end-stage renal disease 2

Optimal Dosing Considerations

• Practice Point 3.6.1 from KDIGO 2024 guidelines states: "RASi (ACEi or ARB) should be administered using the highest approved dose that is tolerated to achieve the benefits described because the proven benefits were achieved in trials using these doses" 1
• JB is currently on losartan 100 mg daily, which is the maximum recommended dose 2

Blood Pressure Management

• JB's blood pressure is well-controlled (122/82 mmHg) on his current regimen
• The fact that BP is at goal is NOT a reason to discontinue ARB therapy in a patient with CKD and severely increased albuminuria 1

Potassium Management

• JB's serum potassium is 4.9 mmol/L, which is elevated but still within normal range
• Practice Point 3.6.3 from KDIGO 2024 states: "Hyperkalemia associated with use of RASi can often be managed by measures to reduce the serum potassium levels rather than decreasing the dose or stopping RASi" 1
• Only consider reducing or discontinuing ARB for "uncontrolled hyperkalemia despite medical treatment" 1

Monitoring Recommendations

1. Potassium Monitoring:

   • Check serum potassium within 2-4 weeks 1
   • Consider dietary potassium restriction if levels rise further

2. Renal Function Monitoring:

   • Monitor serum creatinine within 2-4 weeks 1
   • Continue ARB therapy unless serum creatinine rises by more than 30% 1

3. Blood Pressure Monitoring:

   • Continue regular BP monitoring to ensure it remains at target
   • Target BP for CKD patients is <130/80 mmHg 1

Important Considerations and Pitfalls

When to Consider Dose Reduction or Discontinuation

According to KDIGO 2024 Practice Point 3.6.5, consider reducing the dose or discontinuing ACEi or ARB only in the setting of:

• Symptomatic hypotension (not present in JB)
• Uncontrolled hyperkalemia despite medical treatment (not present in JB)
• To reduce uremic symptoms while treating kidney failure (eGFR <15 ml/min per 1.73 m²) (not applicable to JB) 1

Race-Specific Considerations

• While some antihypertensive drugs have smaller effects in Black patients, the renoprotective effects of ARBs in patients with severely increased albuminuria are beneficial regardless of race when albuminuria is present 1
• The current recommendation to continue losartan is based on the presence of severely increased albuminuria, which is the primary indication for ARB therapy in this case 1

Potential for Additional Therapies

• Consider adding an SGLT2 inhibitor if JB develops diabetes or if his eGFR is ≥20 mL/min/1.73 m² 1
• A nonsteroidal mineralocorticoid receptor antagonist could be considered if albuminuria persists despite maximum tolerated ARB dose 1

By continuing losartan 100 mg daily, JB will receive optimal renoprotection while maintaining good blood pressure control, which is essential for reducing the progression of kidney disease and cardiovascular risk.