Aldactone 25 mg film-coated tablets – patient leaflet, side effects, dosage

1. What Aldactone is and what it is used for

Aldactone contains the active substance spironolactone. Aldactone belongs to a group of medicines called ‘diuretics’ – you may know these as ‘water’ tablets. You may have gone to your doctor because you had swollen ankles or were short of breath. This can happen when your heart’s pumping action has become weak because of too much fluid in your body. This is called ‘congestive heart failure’. Pushing extra fluid around your body means your heart has to work harder. Your doctor has given you Aldactone to help you lose the extra fluid from your body. This will mean your heart has to do less work. You lose the extra fluid as urine, so you may need to go to the toilet more often while you are taking Aldactone.

You can also take Aldactone for the following illnesses:

• ‘Nephrotic syndrome’ - a kidney disorder that causes too much fluid in your body
• ‘Ascites’ - too much fluid in your abdomen and ‘oedema’ - accumulation of fluid beneath skin or in one or more cavities of the body that produces swelling, for example caused by cirrhosis of the liver
• ‘Malignant ascites’- fluid containing cancer cells that collect in the abdomen
• ‘Primary aldosteronism’ - extra fluid in your body caused by too much of a hormone called ‘aldosterone’.

If you have these illnesses, Aldactone will help your body to get rid of the extra fluid. You must talk to a doctor if you do not feel better or if you feel worse.

Children should only be treated under guidance of a paediatric specialist.

2. What you need to know before you take Aldactone

Do not take Aldactone if:

• you are allergic to spironolactone or any of the other ingredients of this medicine (listed in section 6)
• you cannot pass urine
• you have severe kidney disease
• you have Addison’s disease; (a hormone deficiency characterised by extreme weakness, loss of weight and low blood pressure)
• you have hyperkalaemia (raised blood potassium levels)
• you are breast-feeding
• you are taking water tablets (potassium sparing diuretics) or any potassium supplements

• you are taking eplerenone (a medicine for high blood pressure). Children with moderate to severe kidney disease must not take Aldactone.

  Warnings and precautions

  Talk to your doctor or pharmacist before taking Aldactone if:

  • you suffer from kidney disease especially children with hypertension or liver disease. Your doctor will routinely assess you particularly if you are elderly
  • you have difficulty passing urine
  • you have a disease that can result in electrolyte balance disturbance in your blood such as potassium or sodium
  • you have severe heart failure
  • you are pregnant

If you experience reduced kidney function or kidney failure you may have severe increases in the levels of potassium in your blood. This can affect the way your heart functions and in extreme cases this can be fatal. Concomitant administration of Aldactone with certain medicines, potassium supplements and food rich in potassium may lead to severe hyperkalaemia (increased potassium blood level). The symptoms of severe hyperkalaemia might include muscle cramps, irregular heart rhythm, diarrhoea, nausea, dizziness or headache.

Other medicines and Aldactone

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. Your doctor may wish to alter your dose of Aldactone if you are taking any of the following:

• digoxin or carbenoxolone
• medicines for high blood pressure including angiotensin-converting enzyme (ACE) inhibitors
• other diuretics
• non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, indomethacin, mefenamic acid or ibuprofen
• potassium supplements
• heparin or low molecular weight heparin (medicines used to prevent blood clots)
• antipyrine
• medicines known to cause hyperkalaemia (raised blood potassium levels)
• trimethoprim and trimethoprim-sulfamethoxazole
• Spironolactone use can increase lithium concentration in your blood. Your doctor should monitor your blood-lithium levels regularly if you are taking both medications.

Aldactone reduces your responsiveness to noradrenaline. If you are going to have an operation where you will be given an anaesthetic, tell the doctor in charge that you are taking Aldactone.

Tell your doctor, if you are using abiraterone for treatment of prostate cancer.

Tell your doctor, if you are using mitotane for treatment of malignant tumours of the adrenal glands. This medicine should not be used together with mitotane.

Aldactone with food, drink and alcohol

See section 3 ‘How to take Aldactone’.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Pregnancy

There are limited data from the use of Aldactone in pregnant women. Your doctor will only prescribe Aldactone if the potential benefit outweighs the potential risk.

Breast-feeding

Aldactone should not be used if you are breast-feeding. You should discuss the use of Aldactone with your doctor, who will advise you to consider an alternative method of feeding your baby while you are taking this medicine.

Driving and using machines

Take care if you drive or operate machinery. Drowsiness and dizziness have been associated with Aldactone treatment and this may affect your ability to drive or operate machinery safely.

3. How to take Aldactone

Always take this medicine exactly as your doctor or pharmacist has told you. Check with your doctor or pharmacist if you are not sure. The pharmacist’s label on the pack also gives this information. The number of tablets you need to take depends on your illness.

Recommended dose

This medicine should be taken once a day with food. Adults

The adult dose varies from 25mg to 400mg spironolactone a day, depending on the condition being treated. If you are not sure how much to take, ask your doctor or pharmacist.

Elderly

Your doctor will start you on a low starting dose and gradually increase the dosage as needed to obtain the desired effect. Use in children and adolescents

If you are giving Aldactone to a child, the number of tablets you give will depend on the child’s weight. Your doctor will work out the number of tablets that you should give.

If you take more Aldactone than you should

If you accidentally take too many tablets, contact your doctor or nearest hospital accident and emergency department immediately. The symptoms of an overdose are feeling drowsy, dizzy, feeling dehydrated and you may feel confused. You may also feel or be sick, suffer from diarrhoea and may have skin rashes that will appear as flat red areas of skin with overlapping small raised bumps. Changes in your blood sodium and potassium levels may leave you feeling weak and suffering from tingling, prickling or numbness of the skin and/or muscle spasms but these symptoms are unlikely to be associated with severe overdosage.

If you forget to take Aldactone

If you forget to take your tablet, take it as soon as you remember, unless it is almost time for your next dose. Do not take a double dose to make up for a forgotten dose.

If you stop taking Aldactone

It is important to keep taking Aldactone until your doctor tells you to stop, even if you start to feel better. If you stop taking the tablets too soon, your condition may get worse. If you have any further questions on the use of this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, this medicine can cause side effects, although not everybody gets them.

Tell your doctor immediately if you experience any of the following symptoms after taking this medicine. Although they are very rare, the symptoms can be severe.

• Itchiness and blistering of the skin around the lips and the rest of the body, red or purple rash spreading and forming blisters (Stevens-Johnson syndrome)
• Detachment of the top layer of skin from the lower layers of skin, all over the body (toxic epidermal necrolysis - TEN)
• Skin rash, fever and swelling (which could be symptoms of something more serious, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS))
• Yellow skin and eyes (jaundice)
• Aldactone can cause impairment of liver function
• Irregular heartbeat which can be fatal, tingling sensation, paralysis (loss of muscle function) or difficulty in breathing; which may be symptoms of raised potassium levels in your blood. Your doctor will conduct regular blood tests to monitor potassium and other electrolyte levels. They may stop your treatment if necessary. List of other side effects of Aldactone by frequency:

Very common: may affect more than 1 in 10 people

• Raised potassium in the blood

Common: may affect up to 1 in 10 people

• Confusion
• Dizziness
• Vomiting or feeling sick
• Itching of the skin
• Rash
• Muscle or leg cramps
• Kidney failure or abnormal function
• Breast enlargement in men
• Breast pain (in men)
• Feeling generally unwell

Uncommon: may affect up to 1 in 100 people

• Changes in the breast such as breast lumps
• Disturbances in body electrolytes such as high blood calcium
• Abnormal functioning of the liver

• Skin allergy with development of itchiness and hives, nettle like rash

  • Menstrual problems in women
  • Breast pain (in women)

Not known: frequency cannot be estimated from the available data

• Lowered white blood cell count in blood
• Reduced number of cells that fight infection – white blood cells which make infections more likely
• Reduced number of cells that help with blood clotting which increases risk of bleeding or bruising
• Change in sex drive for both men and women
• Digestion problems, stomach upset

• Skin condition presenting with fluid-filled blisters

  (pemphigoid)

• Hair loss
• Excessive hair growth

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

5. How to store Aldactone

Keep this medicine out of the sight and reach of children. Do not store your tablets above 30°C.

Do not use this medicine after the expiry date which is stated on the blister, carton or bottle label after EXP. The expiry date refers to the last day of that month. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment.

6. Contents of the pack and other information

What Aldactone contains

The active substance is spironolactone. Each Aldactone 25mg tablet contains 25mg of spironolactone. Each Aldactone 50mg tablet contains 50mg of spironolactone and each Aldactone 100mg tablet contains 100mg spironolactone.

The other ingredients are calcium sulfate dihydrate, corn starch, polyvinyl pyrrolidone, magnesium stearate, felcofix peppermint, hypromellose, polyethylene glycol. Aldactone 25mg and Aldactone 100mg tablets contain Opaspray yellow (E171 and E172). Aldactone 50mg tablets contain Opaspray white (E171).

What Aldactone looks like and contents of the pack

Aldactone 25mg tablets are buff, film coated tablets engraved “SEARLE 39” on one side.

Aldactone 50mg tablets are white, film-coated tablets engraved “SEARLE 916” on one side.

Aldactone 100mg tablets are buff, film coated tablets engraved “SEARLE 134” on one side.

Aldactone 25mg tablets come in amber glass or plastic bottles and PVC/foil blister packs containing 100 or 500 tablets; HDPE containers of 50 or 1,000 tablets and PVC/foil calendar packs of 28 tablets. Aldactone 50mg tablets come in amber glass or plastic bottles and PVC/foil blister packs of 50, 100 or HDPE containers of 50, 100 or 500 tablets.

Aldactone 100mg tablets come in amber glass or plastic bottles and PVC/foil blister packs containing 100 or 500 tablets; HDPE containers of 50 or 1,000 tablets and PVC/foil calendar packs of 28 tablets. All pack sizes may not be marketed.

Marketing Authorisation Holder and Manufacturer Marketing Authorisation Holder

Pfizer Limited

Ramsgate Road

Sandwich, Kent

CT13 9NJ

United Kingdom

Manufacturer

Piramal Healthcare UK Limited

Morpeth

Northumberland

NE61 3YA

This leaflet was last revised in 06/2025.

Ref: AN 23_0 2025-4056-1