A 50-year-old woman seeks follow-up for chronic kidney disease diagnosed during routine laboratory workup before knee surgery. A 24-hour urine shows 1.5 g/day of proteinuria, and urinalysis shows a few granular casts. Her history, physical examination, and screening laboratory findings do not indicate a cause for her chronic kidney disease. A renal ultrasound reveals echogenic kidneys measuring about 9 cm bilaterally without evidence of obstructive uropathy. She takes no medications.
Her blood pressure is 152/92 mm Hg and pulse is 79/min. The physical examination is within normal limits.
The patient's most recent laboratory results are as follows:

Which of the following would be the best therapeutic agent for this patient?

Question

A 50-year-old woman seeks follow-up for chronic kidney disease diagnosed during routine laboratory workup before knee surgery.  A 24-hour urine shows 1.5 g/day of proteinuria, and urinalysis shows a few granular casts.  Her history, physical examination, and screening laboratory findings do not indicate a cause for her chronic kidney disease.  A renal ultrasound reveals echogenic kidneys measuring about 9 cm bilaterally without evidence of obstructive uropathy.  She takes no medications.
Her blood pressure is 152/92 mm Hg and pulse is 79/min.  The physical examination is within normal limits.
The patient's most recent laboratory results are as follows:

Which of the following would be the best therapeutic agent for this patient?

Quizplus · Accepted Answer

This patient with chronic kidney disease (CKD) would benefit most from an ACEI, even though the serum creatinine is 2.7 mg/dL and potassium is 4.5 mEq/L. Inhibition of the renin-angiotensin-aldosterone system slows progression of even advanced proteinuric CKD but can cause life-threatening hyperkalemia. Rather than withholding these agents in CKD patients, careful dose titration and close clinical monitoring can result in excellent blood pressure control, reduction in proteinuria, and lower frequency of adverse effects. The proteinuria goal of < 1000 mg/day is recommended in patients with proteinuric nondiabetic CKD. Goal blood pressure is < 130/80 mm Hg in proteinuric CKD patients and < 140/90 mm Hg in nonproteinuric CKD patients. Risk factors for hyperkalemia with ACEIs or ARBs include baseline potassium > 4.5 mEq/L, potassium supplementation, potassium-sparing diuretic, NSAID use, and diabetes mellitus. This patient should follow a low-potassium diet, avoid NSAIDS, and start an ACEI or ARB. Current guidelines suggest rechecking blood pressure, serum creatinine, and potassium in 2 weeks. Subsequent testing intervals depend on the results. (Choice A) The non-dihydropyridine calcium channel blockers (eg, diltiazem and verapamil) have significant antiproteinuric effects and can be used as second-line agents. The dihydropyridine calcium channel blockers (eg, amlodipine and nifedipine), however, do not have significant antiproteinuric effects. (Choice C) Beta blockers may decrease blood pressure but are not as effective in decreasing progression of proteinuric CKD. (Choice D) Clonidine has many troubling side effects and does not significantly slow progression of proteinuric CKD. (Choice E) Hydrochlorothiazide would likely not exert a significant natriuretic effect at this patient's level of glomerular filtration. Educational objective: ACEIs and ARBs are effective agents that can lower blood pressure and slow progression of proteinuric chronic kidney disease, even in patients with serum creatinine concentrations up to 3 mg/dL. With careful dietary instruction and monitoring, ACEI therapy is appropriate for many of these patients. __________ References: Potassium homeostasis and renin-angiotensin-aldosterone system inhibitors. (http://www.ncbi.nlm.nih.gov/pubmed/20150448) Efficacy and safety of benazepril for advanced chronic renal insufficiency. (http://www.ncbi.nlm.nih.gov/pubmed/16407508) Predicting the risk of hyperkalemia in patients with chronic kidney disease starting lisinopril. (http://www.ncbi.nlm.nih.gov/pubmed/20112435)

A 50-Year-Old Woman Seeks Follow-Up for Chronic Kidney Disease Diagnosed