Spironolactone is a potassium-sparing diuretic and blood pressure medication. It is used to treat high blood pressure, certain types of swelling, heart failure, and primary hyperaldosteronism.

In some cases, spironolactone may also be prescribed for acne or hair loss because of its antiandrogen effects. However, these are off-label uses and have not been approved by the FDA for these conditions.

Spironolactone is available in the United States as 25 mg, 50 mg, and 100 mg tablets. It is sold as a generic medication and under the brand name Aldactone and should only be used as directed by a healthcare provider.

What it is used for

Spironolactone is indicated for:

High blood pressure that is not adequately controlled with other medications;
Swelling and ascites caused by liver cirrhosis;
Swelling associated with nephrotic syndrome when treatment of the underlying condition, fluid and sodium restriction, and other diuretics have not provided an adequate response;
NYHA class III or IV heart failure with reduced ejection fraction;
Short-term treatment before surgery for primary hyperaldosteronism;
Long-term treatment of primary hyperaldosteronism in people who cannot undergo surgery.

Spironolactone is a potassium-sparing diuretic that helps the kidneys eliminate excess sodium and water through urine while reducing potassium loss. It also blocks the effects of aldosterone, a hormone that can contribute to fluid retention and high blood pressure.

Spironolactone for acne

Spironolactone may be effective for treating acne because its antiandrogen effects can reduce oil production in the skin.

However, acne is not included among the FDA-approved indications for spironolactone. When prescribed for acne, it is being used off-label.

Does spironolactone cause weight loss?

Spironolactone does not cause fat loss because it does not increase energy expenditure or reduce appetite.

However, it may cause a temporary decrease in body weight by increasing the amount of water eliminated through urine. This can reduce swelling caused by certain medical conditions.

How to take it

Spironolactone should be taken by mouth with water at the times prescribed by a healthcare provider.

It may be taken with or without food, but it should be taken consistently in the same way each day.

Spironolactone doses vary depending on the condition being treated and may include:

1. High blood pressure

The recommended starting dose for high blood pressure is 25 to 100 mg per day, taken as a single dose or divided into smaller doses.

A healthcare provider may adjust the dose at intervals of at least two weeks based on the response to treatment. Doses above 100 mg per day generally do not provide an additional reduction in blood pressure.

2. Heart failure

The recommended starting dose of spironolactone for NYHA class III or IV heart failure with reduced ejection fraction is 25 mg once daily.

People who tolerate this dose may have it increased to 50 mg once daily when clinically appropriate. Those who develop high potassium levels may have their dose reduced to 25 mg every other day.

For people with moderately impaired kidney function, a healthcare provider may recommend starting with 25 mg every other day because of the increased risk of high blood potassium levels.

3. Liver cirrhosis

For swelling associated with liver cirrhosis, the usual starting dose is 100 mg per day, taken as a single dose or divided into smaller doses.

Treatment should generally be started in a hospital. The dose should be increased gradually based on the person’s response, kidney function, electrolyte levels, and tolerance.

4. Nephrotic syndrome

For adults with swelling associated with nephrotic syndrome, the usual starting dose is 100 mg per day, taken as a single dose or divided into smaller doses.

Spironolactone is generally used for this condition only when treatment of the underlying disease, fluid and sodium restriction, and other diuretics have not produced an adequate response.

5. Swelling and ascites

The usual starting dose for swelling and ascites in adults is 100 mg per day, taken as a single dose or divided into smaller doses.

Treatment should generally be started in a hospital when swelling is caused by liver cirrhosis. The dose should be adjusted gradually by a healthcare provider based on the person’s response and tolerance.

The safety and effectiveness of spironolactone for treating swelling in children have not been established in the current FDA-approved prescribing information.

6. Low potassium levels

Because spironolactone reduces potassium loss, a healthcare provider may use it when treatment with other diuretics causes low blood potassium levels.

Spironolactone should not be used as a routine potassium supplement. Blood potassium levels must be monitored because this medication can cause dangerously high potassium levels.

7. Primary hyperaldosteronism

When primary hyperaldosteronism has been confirmed, spironolactone may be given at a dose of 100 to 400 mg per day before surgery.

For people who cannot undergo surgery, the lowest effective maintenance dose should be determined individually by a healthcare provider.

8. Severe or difficult-to-control high blood pressure

Spironolactone may be used as an add-on treatment when high blood pressure is not adequately controlled with other medications.

The usual starting dose is 25 to 100 mg per day, taken as a single dose or divided into smaller doses. The dose should be adjusted by a healthcare provider based on blood pressure, kidney function, potassium levels, and response to treatment.

Possible side effects

Possible side effects of spironolactone include:

Nausea or vomiting;
Dizziness;
Headache;
Drowsiness;
Leg cramps;
Breast enlargement or tenderness;
Menstrual irregularities;
Erectile dysfunction;
Changes in libido;
Low blood pressure;
Confusion;
Worsening kidney function;
High blood potassium levels.

Less common reactions may include hair loss, excessive hair growth, gastrointestinal problems, changes in liver function, agranulocytosis, leukopenia, thrombocytopenia, and allergic skin reactions.

Rare but serious skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, may also occur.

Medical attention should be sought immediately if symptoms of abnormal potassium or other electrolyte levels develop, such as:

Muscle weakness;
Tingling sensations;
Difficulty moving part of the body;
Muscle pain;
Chest pain;
An irregular heartbeat;
Increased thirst;
Increased urination;
Severe fatigue;
Confusion.

Emergency medical care is also necessary if signs of a severe allergic or skin reaction occur, such as difficulty breathing, swelling of the face or throat, a widespread rash, blistering, or peeling skin.

Who should not take it

Spironolactone should not be used by anyone who is allergic to spironolactone or any other ingredient in the medication.

It is also contraindicated in people with:

High blood potassium levels;
Addison’s disease;
Concomitant use of eplerenone.

People with impaired kidney function may be more likely to develop high potassium levels or worsening kidney function. Kidney function and blood potassium levels should be evaluated before treatment and monitored while taking spironolactone.

Spironolactone should only be used during pregnancy after a healthcare provider has carefully considered its potential risks and benefits. Because of its antiandrogen effects and the potential risk to a male fetus, it should generally be avoided during pregnancy unless it is medically necessary.

Spironolactone and its active metabolite may pass into breast milk in small amounts. A healthcare provider should consider the benefits of breastfeeding and the clinical need for treatment before spironolactone is used while breastfeeding.

Spironolactone: Uses, How to Take, Dosing & Contraindications