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About spironolactone - Brand name: Aldactone

Spironolactone is a type of medicine called a diuretic. These medicines are sometimes called "water tablets" because they make you pee more.

It is also an anti-androgen, which means it stops male hormones, such as testosterone, from working.

Spironolactone is used to treat build-up of fluid in your body (oedema) caused by:

  • heart failure
  • liver disease – it treats build-up of fluid in your abdomen, called ascites
  • kidney disease – it treats a condition that causes your kidneys to leak large amounts of protein into your pee, called nephrotic syndrome
  • high levels of aldosterone (a hormone made by the adrenal glands)

It can also be used to treat high blood pressure (hypertension) when other medicines have not worked.

Spironolactone is only available on prescription. It comes as tablets.

Spironolactone also comes as tablets that contain other diuretics. When it's mixed with furosemide it's called by the brand name Lasilactone. When it's mixed with hydroflumethiazide it's called by the brand name Aldactide.

Key facts

  • You'll usually take spironolactone once a day in the morning. Some people need to take it twice a day. If you're taking it twice a day, take the second dose before 4pm.
  • Take spironolactone with food, to help stop you feeling or being sick.
  • The most common side effect of spironolactone is high potassium levels. Your doctor will give you blood tests while you're taking spironolactone to make sure your potassium levels are stable.
  • Do not have low-sodium salt or salt substitutes, like Lo-Salt, because they contain a lot of potassium. Using these with spironolactone can cause your potassium levels to become too high.
  • Try to limit other food and drink that contain a lot of potassium, including bananas, avocados, pulses, nuts and salmon.

Page last reviewed: 6 July 2022
Next review due: 6 July 2025