What is the clinical significance of impaired renal function, as evidenced by elevated Blood Urea Nitrogen (BUN) and creatinine levels, in a 74-year-old female patient taking aspirin (acetylsalicylic acid), escitalopram, furosemide, metoprolol succinate, and pramipexole?

From the Guidelines

The patient's current furosemide dose of 20mg daily should be reduced to 10mg daily or alternate-day dosing to minimize kidney stress, as evidenced by the elevated BUN and creatinine levels, while closely monitoring blood pressure and adjusting medications as necessary 1. The patient's lab results indicate moderate kidney dysfunction with elevated BUN (46), creatinine (1.63), and reduced eGFR (33), suggesting stage 3 chronic kidney disease. The high BUN/creatinine ratio of 28 points to possible dehydration or prerenal issues. The patient also has mild anemia (Hgb 11.5) but good glycemic control (A1C 6.0). Some key considerations for this patient include:

• Reducing the furosemide dose to decrease kidney stress while monitoring blood pressure, as high-dose furosemide has been associated with worsening renal function 1
• Increasing fluid intake unless contraindicated by heart failure, to help manage dehydration and prerenal issues
• Medication adjustments may be needed as metoprolol and furosemide are primarily renally cleared, and the patient's kidney function is impaired
• The patient should undergo repeat kidney function tests in 1-2 weeks to assess trends, and a nephrology consultation is warranted if kidney function continues to decline
• Dietary modifications including moderate protein restriction (0.8g/kg/day) and reduced sodium intake would be beneficial, as recommended by the European Society of Cardiology 1
• The patient should avoid NSAIDs and other nephrotoxic medications, as they can exacerbate kidney dysfunction 1

From the FDA Drug Label

The clearance of pramipexole was about 75% lower in patients with severe renal impairment (creatinine clearance approximately 20 mL/min) and about 60% lower in patients with moderate impairment (creatinine clearance approximately 40 mL/min) compared with healthy volunteers. In patients with varying degrees of renal impairment, pramipexole clearance correlates well with creatinine clearance. Therefore, creatinine clearance can be used as a predictor of the extent of decrease in pramipexole clearance A lower starting and/or maintenance dose may be appropriate in these patients (see PRECAUTIONS and DOSAGE AND ADMINISTRATION).

The patient has a creatinine clearance of 33 mL/min, which indicates moderate to severe renal impairment.

• The pramipexole clearance is likely to be decreased in this patient, and a lower dose may be necessary.
• The patient is currently taking 0.25 mg of pramipexole daily, and the dose may need to be adjusted based on the patient's renal function 2.
• It is recommended to exercise caution when administering pramipexole to patients with renal disease.