What diuretic is potassium-sparing?

From the Guidelines

Potassium-sparing diuretics, such as spironolactone and eplerenone, are the preferred choice for patients who require a diuretic that spares potassium, as they help maintain or increase serum potassium levels. These medications work by inhibiting sodium reabsorption in the distal tubule and collecting duct of the kidney, which reduces potassium excretion 1. Spironolactone and eplerenone are aldosterone antagonists that block mineralocorticoid receptors, while other potassium-sparing diuretics like amiloride and triamterene directly block epithelial sodium channels.

Key Points to Consider

• Unlike other diuretic classes such as loop diuretics (furosemide) and thiazides (hydrochlorothiazide), which increase potassium excretion and can cause hypokalemia, potassium-sparing diuretics are particularly useful in patients with hypokalemia or those taking medications that deplete potassium 1.
• However, these medications should be used cautiously in patients with kidney dysfunction or those already taking potassium supplements, as they can cause hyperkalemia.
• Regular monitoring of serum potassium levels is recommended when using these medications.

Clinical Application

• The choice of potassium-sparing diuretic may depend on the specific clinical context, such as primary aldosteronism or resistant hypertension, where spironolactone or eplerenone may be preferred 1.
• In patients with symptomatic heart failure, potassium-sparing diuretics may be used in combination with other diuretics to help maintain serum potassium levels 1.

From the FDA Drug Label

Amiloride HCl is a potassium-conserving (antikaliuretic) drug that possesses weak (compared with thiazide diuretics) natriuretic, diuretic, and antihypertensive activity. Amiloride HCl has potassium-conserving activity in patients receiving kaliuretic-diuretic agents Amiloride HCl exerts its potassium sparing effect through the inhibition of sodium reabsorption at the distal convoluted tubule, cortical collecting tubule and collecting duct; this decreases the net negative potential of the tubular lumen and reduces both potassium and hydrogen secretion and their subsequent excretion Triamterene Capsules are potassium-sparing diuretics.

The diuretics that are potassium sparing are:

• Amiloride 2
• Triamterene 3

From the Research

Potassium-Sparing Diuretics

• The following diuretics are potassium-sparing:
  • Spironolactone 4, 5, 6, 7, 8
  • Eplerenone 4, 5, 6, 8
  • Amiloride 4, 6
  • Triamterene 4, 6

Characteristics of Potassium-Sparing Diuretics

• Spironolactone and eplerenone are mineralocorticoid receptor antagonists, which provide effective antihypertensive treatment, especially in low-renin and salt-sensitive forms of hypertension, including resistant hypertension 4, 5, 8
• Eplerenone has fewer progestational and antiandrogenic effects than spironolactone, enhancing tolerability and potentially improving adherence to therapy 4, 5
• Amiloride and triamterene are generally prescribed for essential hypertension as a fixed-dose combination with hydrochlorothiazide 4
• The dose range for spironolactone with resistant hypertension is between 25 mg/d and 50 mg/d, and eplerenone is an appropriate alternative if spironolactone is not tolerated because of sexual side effects 4, 5