How does spironolactone work?
Spironolactone blocks aldosterone, a hormone that causes fluid retention. This helps reduce swelling, lower blood pressure, and balance hormone levels in certain conditions.
What is spironolactone used to treat?
Spironolactone is commonly prescribed for:
- High blood pressure (hypertension)
- Fluid retention (oedema) caused by heart, liver, or kidney disease
- Hormonal acne and excessive hair growth (hirsutism) in women
- Polycystic ovary syndrome (PCOS) (to regulate hormones)
- Heart failure (to improve heart function)
Who can take spironolactone?
Spironolactone is suitable for most adults, but your doctor will assess if it’s right for you.
Who might not be able to take spironolactone?
Spironolactone may not be suitable if you:
- Have severe kidney or liver disease
- Have high potassium levels (hyperkalaemia)
- Have Addison’s disease (a hormone disorder)
- Are taking other potassium-sparing diuretics
Can I take spironolactone if I’m pregnant or breastfeeding?
Spironolactone isn’t usually recommended during pregnancy or while breastfeeding, as it may affect hormone levels in the baby. Speak to your doctor for advice.
What if I miss a dose?
If you forget a dose, take it as soon as you remember. If it’s close to your next dose, skip the missed one—do not take two doses at once.
How effective is spironolactone?
Spironolactone is highly effective at reducing fluid retention, lowering blood pressure, and managing hormonal conditions when taken as prescribed.
What should I do if I take too much?
Taking too much spironolactone can cause severe dehydration, low blood pressure, or dangerously high potassium levels. If you think you’ve taken too much, seek medical help immediately.
What dose of spironolactone is usually taken?
- For high blood pressure: 25mg to 100mg once daily
- For heart failure: 25mg to 50mg once daily
- For fluid retention (oedema): 100mg to 200mg daily
- For hormonal acne/PCOS: 50mg to 200mg daily
Your doctor will determine the correct dose based on your condition.
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What are the side effects of spironolactone?
Common side effects include:
- Frequent urination
- Dizziness or low blood pressure
- High potassium levels (which may cause muscle weakness or irregular heartbeat)
- Breast tenderness or swelling
- Changes in menstrual cycles
Serious side effects, such as severe dizziness, confusion, or irregular heartbeat, require urgent medical attention.
How should I take spironolactone?
Spironolactone is taken as a tablet, once daily, swallowed whole with water.
When should spironolactone be taken?
Spironolactone is usually taken in the morning to avoid frequent urination at night.
What are the brand names for spironolactone?
Spironolactone is available as a generic medicine, but some branded versions include:
- Aldactone
- Spirolactone
Final thoughts
Spironolactone is an effective medication for high blood pressure, fluid retention, and hormonal conditions. To get the best results, take it as prescribed and have regular blood tests to monitor potassium levels. If side effects occur, speak to your doctor or pharmacist.
