A 79-year-old woman has well-controlled hypertension, hyperlipidemia, ischemic heart disease, and type 2 diabetes complicated by diabetic nephropathy and chronic kidney disease that has gradually progressed during the past 5 years.
At her most recent evaluation 3 months ago, her serum creatinine level was 2.4 mg/dL (reference range, 0.6–1.1), with an estimated glomerular filtration rate of 19 mL/min/1.73 m2 (≥60). Her medications include simvastatin, metoprolol, lisinopril, furosemide, calcium acetate, and aspirin.
On examination, her heart rate is 70 beats per minute, and her blood pressure is 132/80 mm Hg. She has clear lungs and trace edema.
Laboratory testing yields the following results:
Patient value Reference range
Hemoglobin (g/dL) 10.0 12.0–16.0
Sodium (mEq/liter) 137 136–145
Potassium (mEq/liter) 4.9 3.5–5.0
Bicarbonate (mEq/liter) 17 21–30
Chloride (mEq/liter) 103 98–106
Blood urea nitrogen (mg/dL) 60 10–20
Creatinine (mg/dL) 2.7 0.6–1.1
Phosphorus (mg/dL) 4.2 3.0–4.5
Uric acid (mg/dL) 8.0 1.5–6.0
Which one of the following treatments is most appropriate for this patient?