spironolactone at a glance
Medicine class
Potassium-sparing diuretic and mineralocorticoid-receptor antagonist.
Available forms
Tablets, oral suspension and oral solutions. Instructions differ between products.
Administration
Take with or just after food. Measure liquids with the supplied device.
Blood tests
Potassium, kidney function and fluid balance may need checking before and during treatment.
What is spironolactone used for?
Selected UK products are licensed for:
Congestive heart failure, including associated oedema.
Ascites and oedema caused by liver cirrhosis.
Malignant ascites.
Oedema associated with nephrotic syndrome.
Diagnosis and treatment of primary aldosteronism.
Essential hypertension, specifically in the Qaialdo licence.
Non-licensed use for persistent acne in adult women because of its anti-androgen effects.
How does spironolactone work?
Spironolactone blocks aldosterone in the kidney, increasing sodium and water loss while reducing potassium loss. It also blocks androgen activity, which explains some hormonal effects and its non-licensed use for acne in women.
spironolactone preparations and strengths
Oral solution
Route: Oral
Strengths: 25 mg/5 mL, 50 mg/5 mL
Oral suspension
Route: Oral
Strengths: 10 mg/mL
Tablet
Route: Oral
Strengths: 12.5 mg, 25 mg, 50 mg, 100 mg
How to take spironolactone
Follow the label and instructions for the specific product supplied.
Take with or just after food.
Measure liquids only with the supplied device; household teaspoons are unsuitable.
Shake Qaialdo thoroughly before measuring it and drink water afterwards. A healthcare professional should identify the correct supplied syringe.
Do not mix Urospir with water or use it through an enteral feeding tube. Switching products requires clinical supervision because Urospir is not bioequivalent to the reference tablet.
Spironolactone Waymade is supplied with a bottle adaptor and oral syringe; rinse the syringe after use.
spironolactone side effects
Common or expected effects
- Dizziness.
- Nausea.
- Tiredness or low energy.
- Muscle or leg cramps.
- Breast tenderness or enlargement, including in men.
- Rash or itching.
- Menstrual changes.
Get urgent medical advice
- High potassium: muscle weakness, numbness, marked tiredness or an irregular heartbeat.
- Serious allergic reaction: difficulty breathing or swelling of the mouth, tongue or throat.
- Severe skin reaction: blistering, peeling or widespread painful rash.
- Kidney injury, potentially causing marked illness, nausea, breathlessness or reduced urine.
- Liver injury, including yellow skin or eyes.
- Unexplained fever, sore throat, bruising or bleeding, which may indicate a blood-cell disorder.
spironolactone in pregnancy
Spironolactone is not usually recommended during pregnancy because human evidence is limited and its anti-androgen action could affect fetal development. A specialist may sometimes consider treatment when maternal heart, kidney or fluid-balance disease makes it necessary. Discuss treatment before conception or promptly after discovering a pregnancy; do not stop an essential prescribed medicine without advice.
spironolactone while breastfeeding
Spironolactone may sometimes be used while breastfeeding after professional review. Selected product information is more restrictive because an active metabolite enters breast milk and infant-effect data are limited. The prescriber should consider the medicine's importance, breastfeeding benefits and the baby's circumstances.
spironolactone interactions
Check prescribed, pharmacy and complementary medicines. Important interactions include:
Potassium supplements and potassium-containing salt substitutes
Can cause dangerous hyperkalaemia and should not be used routinely without clinical direction.
Eplerenone and other potassium-sparing diuretics
Combination use is contraindicated by selected product information because potassium may rise excessively.
Common questions about spironolactone
Answers are fully visible for fast scanning and source review.
Will spironolactone make me urinate more?
It can. It helps the kidneys remove sodium and water, although its diuretic effect may be milder than some other water tablets.
Why are blood tests needed?
Spironolactone can raise potassium and affect kidney function, sometimes without early symptoms.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.