What is Spironolactone: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Spironolactone is a generic prescription diuretic or “water pill,” a medicine that eliminates water by increasing urination. Used with other drugs, it’s a standard treatment for high blood pressure and heart failure, as well as excess fluid pooling in parts of the body (edema). Spironolactone makes kidneys excrete more water and sodium than usual. At the same time, it prevents the loss of potassium, a common problem with other types of diuretics.

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Spironolactone overview

BRAND NAMES:

  • Aldactone, CaroSpir

Generic Names:

  • Spironolactone

Uses:

  • Tablet, oral suspension (liquid)

Therapeutic Classes:

Forms:

  • Tablet, oral suspension (liquid)

How it’s taken:

  • By mouth

What is Spironolactone used for?

Spironolactone is used with other drugs to treat high blood pressure and heart failure. Healthcare providers also use spironolactone as a backup drug for fluid buildup due to liver cirrhosis, kidney disease, or other causes. Common off-label uses include difficult-to-treat acne and unwanted body hair (hirsutism), but neither of these uses is approved by the FDA.

What form(s) does Spironolactone come in

  • Tablet

    • 25 mg

    • 50 mg

    • 100 mg

  • Oral suspension (liquid)

    • 25 mg/5 mL

What are common Spironolactone doses?

  • For heart failure in adults: 25–50 mg taken by mouth once per day

  • For hypertension in adults: 25–100 mg taken by mouth divided into 1–2 doses per day

  • For edema in adults: 25–200 mg taken by mouth daily in single or divided doses

  • For primary hyperaldosteronism in adults: 100–400 mg taken by mouth once per day in preparation for surgery OR lowest effective daily maintenance dose for patients unsuitable for surgery

Common Spironolactone prescriptions

  • Spironolactone
    30 tablets disp pack

  • Spironolactone
    100mg tablet

  • Spironolactone
    25mg tablet

  • Spironolactone
    50mg tablet

How to take Spironolactone

  • Take your medicine as directed. Your dose may need to be changed several times to find what works best for you.

  • This medicine may be taken with or without food, but it should be taken the same way (with or without food) each day.

  • How to take spironolactone tablets

    • Swallow the tablet whole. Do not crush it or try to mix it with food or liquid.

  • How to take spironolactone oral suspension

    • Shake the bottle well before measuring out a dose.

    • Measure the oral liquid medicine with a calibrated oral syringe or similar measuring device. 

    • Oral suspension doses are different from tablet doses. Do not switch from one to another without getting a doctor’s prescription.

  • Store spironolactone tablets or oral suspension at room temperature.

What to do if you miss a dose of Spironolactone

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. 

  • Do not take extra medicine to make up for a missed dose

Spironolactone contraindications

  • This medicine is not right for everyone. 

  • Do not use spironolactone if:

  • You have had an allergic reaction to spironolactone

  • You have Addison’s disease.

Spironolactone warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • Your doctor will do lab tests regularly to check on the effects of this medicine. Keep all appointments.

  • Tell your doctor if you are pregnant or breastfeeding.

  • Tell your doctor if you have:

  • Kidney disease

  • Liver disease

  • Urinary retention (trouble urinating)

  • Diabetes

  • Gout

  • This medicine may cause the following problems: 

  • Low blood pressure

  • Worsening of kidney function

  • Electrolyte imbalance

  • Elevated blood sugar levels

  • Alkalosis

  • Elevated uric acid levels

  • This medicine may make you dizzy or drowsy. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.

  • You should not use the liquid version of spironolactone for doses over 100 mg. Ask the doctor to switch you to tablets.

  • Do not stop using the medicine without talking to the doctor.

  • Keep this medication out of the reach of children.

Spironolactone interactions

  • To avoid potentially hazardous drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medications, and supplements you use before taking spironolactone.

  • Tell other healthcare providers you are using this medicine before they prescribe new medications.

  • Do not use this medicine together with another diuretic called eplerenone.

  • Some medicines may cause problems when combined with spironolactone. Tell your doctor if you are also taking: 

    • Blood pressure medications, particularly ACE inhibitors or angiotensin II receptor blockers (ARBs)

    • Corticosteroids such as prednisone

    • NSAIDs such as aspirin or ibuprofen

    • The heart failure drug digoxin

    • Heparin blood thinners

    • The antibiotic trimethoprim

    • The cholesterol drug cholestyramine

    • Lithium

  • Avoid potassium supplements, potassium salt substitutes, or medicines containing supplements. The doctor may also ask you to avoid foods high in potassium. Combining these with spironolactone could cause high potassium levels in the body.

  • Alcohol, narcotic pain relievers, or sleeping pills may cause you to feel more lightheaded, dizzy, or faint when used with this medicine.

Find more detailed information about spironolactone drug interactions here.

Spironolactone side effects

Serious side effects

Talk to a doctor if you notice any signs or symptoms of a possible serious side effect including:

  • Dry mouth, increased thirst, muscle cramps, uneven heartbeat, confusion, weakness, or numbness, or tingling in your hands, feet, or lips

  • Confusion, weakness, muscle twitching

  • Heart palpitations, chest pain, uneven heartbeat, muscle weakness, numbness in the arms or legs

  • Decreased urination, swelling in the legs, ankles, or feet, fatigue, confusion, irregular heartbeat, chest pain

  • Blood in your stools or dark stools, vomiting blood or material that looks like coffee grounds, abdominal pain

  • Yellow skin or eyes

  • Unusual bleeding, bruising, or weakness

  • Lightheadedness, dizziness, drowsiness, fainting

  • Blistering, peeling, red skin rash

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less serious side effects

  • Fatigue

  • Electrolyte imbalance

  • Dehydration

  • Nausea and vomiting

  • Abdominal pain or cramps

  • Muscle cramps

  • Breast development in men

Find more detailed information about spironolactone side effects here.

Sources:

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