Medically reviewed on December 28, 2017
What is spironolactone?
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 also 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 may also be used for purposes not listed in this medication guide.
Spironolactone has caused tumors in animals but it is not known whether this could occur in people. Do not use this medicine for any condition that has not been checked by your doctor.
Before taking this medicine
You should not use spironolactone if you are allergic to it, or if you have:
Addison's disease (an adrenal gland disorder);
high levels of potassium in your blood (hyperkalemia);
if you are unable to urinate; or
if you are also taking eplerenone.
To make sure spironolactone is safe for you, tell your doctor if you have ever had:
an electrolyte imbalance (such as low levels of magnesium in your blood);
liver disease; or
In animal studies, spironolactone caused certain types of tumors. It is not known whether tumors could occur in people using this medicine. Ask your doctor about your risk.
It is not known whether spironolactone will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.
Spironolactone can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.
How should I take spironolactone?
Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not use this medicine in larger or smaller amounts or for longer than recommended.
Do not share this medicine with another person, even if they have the same symptoms you have.
You may take spironolactone with or without food, but take it the same way each time.
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.
What happens if I miss a dose?
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.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking spironolactone?
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 diet high in salt. Too much salt will cause your body to retain water and can make this medication less effective.
Spironolactone may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.
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.
Spironolactone side effects
Get emergency medical help if you have 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:
a light-headed feeling, like you might pass out;
little or no urination;
signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;
low potassium--uneven heart rate, extreme thirst, increased urination, leg discomfort, muscle weakness or limp feeling; or
signs of other electrolyte imbalances--vomiting, muscle spasms or contractions, numbness or tingly feeling, slow heart rate, weak pulse, headache, confusion, slurred speech, severe weakness, loss of coordination, feeling unsteady.
Common side effects may include:
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.
See also: Side effects (in more detail)
What other drugs will affect spironolactone?
Taking this medicine with other drugs that make you dizzy or lower your blood pressure can worsen these effects. Ask your doctor before taking a sleeping pill, opioid pain medicine, a muscle relaxer, or medicine for anxiety, depression, or seizures.
Tell your doctor about all your current medicines and any you start or stop using, especially:
heart or blood pressure medicine (especially another diuretic);
medicine to prevent a blood clot; or
This list is not complete. Other drugs may interact with spironolactone, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
Copyright 1996-2018 Cerner Multum, Inc. Version: 10.01.
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- Drug class: aldosterone receptor antagonists
Other brands: CaroSpir