Should we hold Candasartan (candesartan) in a patient with impaired renal function?

Management of Candesartan in Impaired Renal Function

Yes, candesartan should be held in a patient with impaired renal function and blood work should be reassessed before considering restarting the medication. 1, 2

Rationale for Holding Candesartan

Angiotensin receptor blockers (ARBs) like candesartan can cause significant adverse effects in patients with impaired renal function:

• ARBs can cause worsening of renal function, particularly in patients whose renal function depends on the renin-angiotensin system 1
• Hyperkalemia is a common complication in patients with renal impairment taking ARBs 1
• Patients with renal insufficiency show elevated serum concentrations of candesartan, with approximately doubled AUC and Cmax in those with severe renal impairment 2

Assessment Protocol

1. Check current renal function parameters:

   • Serum creatinine
   • Estimated glomerular filtration rate (eGFR)
   • Serum electrolytes, particularly potassium

2. Evaluate the severity of renal impairment:

   • Mild impairment (CrCl 60-90 ml/min): No dose adjustment required
   • Moderate impairment (CrCl 30-60 ml/min): No dose adjustment required, but closer monitoring
   • Severe impairment (CrCl ≤30 ml/min): Safety not established; avoid use 2

When to Hold Candesartan

Hold candesartan immediately if:

• Serum creatinine rises to >310 μmol/L (>3.5 mg/dL) 1
• Potassium rises to >6.0 mmol/L 1
• Patient shows signs of acute kidney injury
• Patient has severe renal impairment (CrCl ≤30 ml/min) 2

Monitoring and Reassessment

After holding candesartan:

1. Monitor blood chemistry closely
2. Reassess renal function and electrolytes within 3-7 days
3. Consider specific treatment of renal dysfunction if needed 1

Considerations for Restarting

If renal function improves and stabilizes:

• Consider restarting at a lower dose (4 mg daily) 1
• Monitor renal function and electrolytes within 1 week of restarting 1
• Titrate dose cautiously, if at all

Special Considerations

• Patients with bilateral renal artery stenosis are at particularly high risk for worsening renal function with ARBs 3
• Volume-depleted patients (e.g., those on diuretics) are at higher risk for acute kidney injury 2
• Elderly patients may have higher plasma concentrations of candesartan (approximately 80% higher AUC) 2

Important Caveats

• Never combine an ARB with both an ACE inhibitor and aldosterone antagonist due to high risk of renal dysfunction and hyperkalemia 1
• Candesartan cannot be removed by hemodialysis 2
• Even low doses of candesartan can affect renal hemodynamics 4

In conclusion, the safest approach is to hold candesartan in a patient with impaired renal function, reassess blood work, and only consider restarting at a lower dose if renal function improves and stabilizes.