MKSAP 19 "Quiz Me!" Question: Answer and Critique

Answer

B: Discontinue hydrochlorothiazide; begin furosemide

Educational Objective

Treat hypertension in a patient with chronic kidney disease and an estimated glomerular filtration rate <30 mL/min/1.73 m2.

Critique

The most appropriate treatment for this patient is to discontinue hydrochlorothiazide and begin furosemide (Option B). Because sodium retention and volume overload are major contributory factors in the hypertension of chronic kidney disease (CKD), dietary sodium restriction to <2000 mg/d and addition of a diuretic are both essential for control of blood pressure (BP), especially in advanced CKD. Higher doses of diuretics are required in patients with CKD due to decreased glomerular filtration rate (GFR). Hydrochlorothiazide is not an effective diuretic in this patient who has advanced CKD with an estimated GFR (eGFR) <20 to 30 mL/min/1.73 m2, as evidenced by his elevated BP, lower extremity edema, and hyperkalemia after 1 month of treatment. Loop diuretics, dosed two or three times daily, are more potent diuretics and preferred in patients who have advanced CKD with an eGFR <20 to 30 mL/min/1.73 m2.

Eplerenone (Option A) is not appropriate treatment for this patient because of several factors. The addition of an aldosterone receptor blocker such as eplerenone to an ACE inhibitor such as lisinopril will result in dual renin-angiotensin system inhibition and will further increase the serum potassium level. Additionally, potassium-sparing diuretics, such as aldosterone receptor blockers (spironolactone or eplerenone) or epithelial sodium channel blockers (amiloride), are weaker diuretics. Although aldosterone receptor blockers are recommended for certain patients with resistant hypertension, they are not first-line diuretic agents for BP management in patients with CKD and eGFR <20 to 30 mL/min /1.73 m2.

Increasing this patient's dose of hydrochlorothiazide (Option C) will not reduce this patient's BP or edema. Thiazide diuretics such as hydrochlorothiazide become increasingly ineffective as GFR decreases.

According to the American College of Cardiology/American Heart Association, adults with hypertension and CKD should be treated to a BP goal of <130/80 mm Hg. Continuing the current management (Option D) is inappropriate, as the patient has not achieved the desired BP target, and has edema and hyperkalemia.

Key Points

Sodium retention and volume overload are major contributory factors in the hypertension of chronic kidney disease.

Loop diuretics, dosed two or three times daily, are preferred to thiazide diuretics in patients with hypertension and an estimated glomerular filtration rate <20 to 30 mL/min/1.73 m2.

Bibliogrpahy

Hamrahian SM, Falkner B. Hypertension in chronic kidney disease. Adv Exp Med Biol. 2017;956:307-325. PMID: 27873228 doi:10.1007/5584_2016_84

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