When your body holds onto too much fluid, it can raise blood pressure, strain your heart, or make you feel swollen and tired. That’s where potassium-sparing diuretics, a type of medication that helps your kidneys remove extra water without pulling out too much potassium. Also known as K-sparing diuretics, they’re often used when other diuretics leave you low on this key mineral. Unlike loop or thiazide diuretics that flush out potassium along with fluid, these drugs let you pee out the excess water while keeping potassium levels stable—critical for heart rhythm and muscle function.
Potassium-sparing diuretics don’t work the same way as other water pills. They target the kidney’s collecting ducts, blocking sodium reabsorption without affecting potassium. This makes them slower to act but safer for long-term use, especially if you’re already on meds that lower potassium—like ACE inhibitors or certain heart failure drugs. They’re often paired with other diuretics to balance out side effects. Common ones include spironolactone, eplerenone, amiloride, and triamterene. Spironolactone, for example, is also used for hormonal acne and aldosterone-related conditions, while eplerenone is preferred in heart failure patients who need fewer hormonal side effects.
These drugs aren’t for everyone. If you have kidney problems, high potassium levels, or take certain supplements like potassium pills or salt substitutes, they can be dangerous. That’s why your doctor checks your blood work regularly. They’re also not first-line for high blood pressure alone—usually reserved for when other treatments aren’t enough or when you’re at risk of low potassium. People with heart failure, liver cirrhosis, or certain hormone imbalances often benefit most. And because they can interact with other meds—like NSAIDs, lithium, or even some antibiotics—it’s important to tell your provider everything you’re taking.
You’ll find posts here that dive into how these drugs interact with other treatments, what side effects to watch for, and how they fit into broader health plans. Some compare them to other diuretics. Others look at how they affect people with conditions like hypertension or edema. You’ll also see how diet, kidney function, and other medications play into whether they’re the right choice for you. Whether you’re just starting one or have been on it for years, this collection gives you real-world insights—not just textbook definitions.
