Spironolactone is a potassium-sparing diuretic (water pill) that prevents your body from absorbing too much salt and keeps your potassium levels from getting too low.

Spironolactone is used to diagnose or treat a condition in which you have too much aldosterone in your body. Aldosterone is a hormone produced by your adrenal glands to help regulate the salt and water balance in your body.

Spironolactone also treats fluid retention (edema) in people with congestive heart failure, cirrhosis of the liver, or a kidney disorder called nephrotic syndrome. This medication is also used to treat or prevent hypokalemia (low potassium levels in the blood).

Spironolactone may also be used for purposes not listed in this medication guide.

You should not use spironolactone if you are allergic to it, or if you have kidney disease, high levels of potassium in your blood, or if you are unable to urinate. Do not use potassium supplements or other diuretics while you are taking spironolactone.

Before using this medication, tell your doctor if you have liver disease, or if you use a steroid or another diuretic.

Drinking alcohol can increase certain side effects of spironolactone.

Avoid a diet high in salt. Too much salt will cause your body to retain water and can make this medication less effective.

Do not use salt substitutes or low-sodium milk products that contain potassium. These products could cause your potassium levels to get too high while you are taking spironolactone.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

If you are being treated for high blood pressure, keep using this medication even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

You should not use spironolactone if you are allergic to it, or if you have:

• kidney disease, or if you are unable to urinate;

• high levels of potassium in your blood (hyperkalemia); or

• if you are taking potassium supplements or other potassium-sparing diuretics such as Aldactazide, amiloride (Midamor, Moduretic), or triamterene (Dyrenium, Dyazide, Maxzide).

To make sure you can safely take spironolactone, tell your doctor if you have any of these other conditions:

• heart disease;

• liver disease; or

• if you are using a steroid, or another diuretic.

FDA pregnancy category C. It is not known whether spironolactone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

Spironolactone passes into breast milk and could cause harm to a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.