Spironolactone
Also known as: Aldactone
What it's for
Spironolactone is a water tablet that keeps potassium in your body. It treats heart failure, liver disease, and conditions with too much of a hormone called aldosterone.
Comes as: Tablets
How to take it
- Adults: Usually 25mg to 200mg daily, depending on the condition.
- May be taken once daily or split into smaller doses.
- Take with or after food to help absorption.
- Your doctor will check your potassium levels regularly.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Feeling sick or stomach pain
- Breast tenderness or enlargement in men
- Irregular periods in women
- Feeling tired
The leaflet inside the packet lists all known side effects.
Important safety points
- Can raise potassium to dangerous levels - avoid potassium supplements
- Avoid salt substitutes (they contain potassium)
- Tell your doctor if you have kidney problems
- Not suitable during pregnancy
Get medical help urgently if…
- You have muscle weakness or an irregular heartbeat (signs of high potassium)
- You have severe stomach pain or vomiting
- You have difficulty breathing
- You have confusion or feel very unwell
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.