You should not use spironolactone if you have kidney disease, high levels of potassium in your blood, Addison's disease (an adrenal gland disorder), if you are unable to urinate, or if you are also taking eplerenone.

In animal studies, spironolactone caused certain types of cancers or tumors. It is not known whether these effects would occur in people using this medicine. Ask your doctor about your risk.

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, or if you are unable to urinate;

Addison's disease (an adrenal gland disorder);

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

if you are also taking eplerenone.

To make sure spironolactone is safe for you, tell your doctor if you have:

liver disease;

heart disease;

an electrolyte imbalance (such as low levels of magnesium in your blood); or

if you take an NSAID (nonsteroidal anti-inflammatory drug), cholestyramine, heparin, lithium, heart or blood pressure medication, potassium supplements, steroid medicine, or another diuretic.

In animal studies, spironolactone caused certain types of tumors, some of which were cancerous. However, very high doses are used in animal studies. It is not known whether these effects would occur in people using regular doses. Ask your doctor about your risk.

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 can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.

While using spironolactone, you may need frequent blood tests.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using spironolactone.

If you need surgery, tell the surgeon ahead of time that you are using spironolactone. You may need to stop using the medicine for a short time.

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.

Store at room temperature away from heat, light, and moisture.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line .

Drinking alcohol can increase certain side effects of spironolactone.

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 a high-salt diet. Too much salt will cause your body to retain water, which may reduce the effectiveness of this medicine.

Spironolactone may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

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.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using spironolactone and call your doctor at once if you have:

signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;

high potassium--slow heart rate, weak pulse, muscle weakness or limp feeling, tingly feeling;

low sodium--confusion, slurred speech, hallucinations, severe weakness, loss of coordination, feeling unsteady, seizure (convulsions), fainting, shallow breathing (breathing may stop); or

symptoms of any electrolyte imbalance--dry mouth, increased thirst, drowsiness, lack of energy, restless feeling, confusion, nausea, vomiting, increased urination, muscle cramps or weakness, fast heart rate, little or no urinating, or feeling like you might pass out.

Common side effects may include:

mild nausea or vomiting, diarrhea;

breast swelling or tenderness;

dizziness, headache, mild drowsiness;

leg cramps; or

impotence, difficulty having an erection.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Taking this medicine with other drugs that make you dizzy or lower your blood pressure can worsen these effects. Ask your doctor before taking spironolactone with a narcotic pain medicine, muscle relaxer, or medicine for anxiety or seizures.

Other drugs may interact with spironolactone, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Your pharmacist can provide more information about spironolactone.