From the Guidelines
Potassium sparing refers to medications or treatments that prevent the loss of potassium from the body, particularly through the kidneys, and is crucial in maintaining normal potassium levels in the bloodstream, thereby reducing the risk of morbidity and mortality associated with potassium imbalance. These agents work by inhibiting the excretion of potassium in urine, and are often used to treat conditions like heart failure, high blood pressure, or edema, especially when other diuretics that cause potassium loss are also being used 1. The mechanism of action varies by drug - some block aldosterone receptors (spironolactone, eplerenone) while others directly block sodium channels in the kidney's collecting ducts (amiloride, triamterene) 1.
Key Points to Consider
- Common potassium-sparing medications include spironolactone, eplerenone, amiloride, and triamterene, with aldosterone antagonists like spironolactone and eplerenone being preferred over other potassium-sparing diuretics 1.
- When taking potassium-sparing medications, patients should be aware of the risk of developing high potassium levels (hyperkalemia), particularly if they have kidney problems or take potassium supplements, and regular blood tests to monitor potassium levels are typically recommended 1.
- The use of potassium-sparing diuretics should be guided by the patient's renal function, with caution advised in patients with reduced glomerular filtration rate (GFR) 1.
- The dosage of potassium-sparing diuretics should be adjusted according to the patient's response and renal function, with typical dosages ranging from 12.5-50 mg for spironolactone and eplerenone, and 2.5-50 mg for amiloride and triamterene 1.
From the FDA Drug Label
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs): In some patients, the administration of an NSAID can reduce the diuretic, natriuretic, and antihypertensive effect of loop, potassium-sparing, and thiazide diuretics
- Potassium-sparing refers to a type of diuretic that helps the body retain potassium, rather than losing it as a result of increased urine production.
- The term potassium-sparing is used to describe diuretics that do not cause the body to lose potassium, in contrast to other types of diuretics that can lead to potassium loss 2.
- In the context of diuretic therapy, potassium-sparing is an important consideration, as excessive potassium loss can lead to hypokalemia and other complications 3.
From the Research
Definition of Potassium Sparing
- Potassium sparing refers to a type of diuretic that helps the body retain potassium while still removing excess fluid [(4,5,6)].
- These diuretics work by acting on the distal parts of the nephron, from the late distal tubule to the collecting duct, to reduce sodium reabsorption and decrease potassium excretion 6.
Mechanism of Action
- Potassium sparing diuretics, such as spironolactone, amiloride, and triamterene, inhibit the reabsorption of sodium and the secretion of potassium in the distal tubule and collecting duct 6.
- This leads to a decrease in the lumen-negative transepithelial potential difference, which reduces the driving force for potassium movement into the tubular lumen and thus decreases potassium excretion 6.
Examples of Potassium Sparing Diuretics
- Spironolactone is a potassium sparing diuretic that is used to treat heart failure, resistant hypertension, and edema in patients with cirrhosis [(4,5)].
- Amiloride and triamterene are also potassium sparing diuretics that work by blocking the luminal membrane sodium channel and reducing sodium transport 6.