Spironolactone for heart failure

This leaflet is for parents and carers about how to use this medicine in children. Our information may differ from that provided by the manufacturers, because their information usually relates to adults. Read this leaflet carefully. Keep it somewhere safe so that you can read it again.

Your child should not take potassium supplements or eat foods that contain a lot of potassium.

Name of medicine

Spironolactone (Spy-ron-noh-lak-tone)

Brand name: Aldactone

Why is it important for my child to take Spironolactone?

Spironolactone helps your child’s heart to work better. It helps them to make more urine (wee) and therefore lose unnecessary extra fluid from the body. This reduces the work that the heart has to do. Medicines that help the body to lose water are called diuretics (sometimes referred to as ‘water tablets’).

Spironolactone is a special type of diuretic called a potassium-sparing diuretic because, unlike some other diuretics, it does not cause the body to lose potassium. Because of this, it is often used at the same time as other diuretics.

What is Spironolactone available as?

  • Tablets: 25 mg, 50 mg, 100 mg
  • Liquid medicine (suspension): 5, 10, 25, 50 or 100 mg in 5 mL

When should I give Spironolactone

The Spironolactone is usually given twice each day. Give one dose in the morning and one in the evening. Ideally these times are 10–12 hours apart. For example, this could be between 7am and 8am and between 7pm and 8pm.

Give the medicine at about the same time(s) each day so that this becomes part of your child’s daily routine, which will help you to remember.

How much should I give?

Your doctor will work out the amount of Spironolactone (the dose) that is right for your child. The dose will be shown on the medicine label.

It is important that you follow your doctor’s instructions about how much to give.

How should I give Spironolactone?


  • Tablets should be swallowed with a glass of water, squash or juice. Your child should not chew the tablets.
  • You can crush the tablet and mix it with a small amount of soft food such as yogurt, honey, or mashed potato. Make sure your child swallows it straight away, without chewing.

Liquid medicine

  • Shake the medicine well. Measure out the right amount using an oral syringe or a medicine spoon. You can get these from your pharmacist. Do not use a kitchen teaspoon as it will not give the right amount.

When should the medicine start working?

It may take a few days to see the diuretic effect of spironolactone. The effects on the heart may be seen over weeks to months. 

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of Spironolactone, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of Spironolactone, do not give them another dose. Wait until the next normal dose.

If your child is sick again, seek advice from your family doctor, nurse, pharmacist, or hospital. They will decide what to do based on your child’s condition and the specific medicine involved.

What if I forget to give it?

If you usually give it twice a day: If you remember up to 4 hours after you should have given a dose, give your child the missed dose. For example, if you usually give a dose at about 7am, you can give the missed dose at any time up to 11am. If you remember after that time, do not give the missed dose. Give the next dose as usual.

Never give a double dose of Spironolactone.

What if I give too much?

If you think you may have given your child too much Spironolactone, contact your doctor or local NHS services (details at end of leaflet). Have the medicine or packaging with you if you telephone for advice.

It can be dangerous to give too much Spironolactone.

Are there any possible side effects?

We use medicines to make our children better, but sometimes they have other effects that we don’t want (side effects).

Side effects you must do something about

If your child gets a yellowish tinge to the skin or whites of the eyes, contact your doctor straight away, as there may be a problem with their liver.

If your child’s heart beat seems irregular (they may say
that it feels fluttery), they have tingling feelings, paralysis
(difficulty moving) or difficulty breathing, take them to
the hospital straight away, as they may have too much
potassium in their blood.

Other side-effects you need to know about

  • Boys may notice mild breast development. Discuss with your doctor if this happens.

  • Your child may feel dizzy or light-headed when they stand up. Encourage them to sit down for a short time after taking the medicine and to stand up slowly and to sit or lie down if they feel dizzy or light-headed.

  • Girls may find that their periods become irregular. Contact your doctor if this happens.

  • Your child may feel generally unwell, feel sick or be sick (vomit) or get stomach cramps or have diarrhoea. They may also get cramps in the legs. These effects should wear off as your child’s body gets used to the medicine. If they are still a problem after a week, contact your doctor for advice.

There may sometimes be other side effects that are not listed above. If you notice anything unusual and are concerned, contact your doctor. You can report any suspected side effects to a UK safety scheme at

Can other medicines be given at the same time as Spironolactone?

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Spironolactone should not be taken with some medicines. Tell your doctor or pharmacist about any other medicines your child is taking before giving Spironolactone.
  • Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal and complementary medicines.

Is there anything else I need to know about this medicine?

Your child should not take potassium supplements. Ask your doctor or a dietician for advice and a diet sheet if necessary.

Your doctor may do blood tests to check the levels of potassium and other substances in your child’s blood.

General advice about medicines

  • Try to give medicines at about the same times each day, to help you remember.
  • Only give this medicine to your child. Never give it to anyone else, even if their condition appears to be the same, as this could do harm.
  • Make sure that you always have enough medicine. Order a new prescription at least 2 weeks before you will run out.
  • Make sure that the medicines you have at home have not reached the ‘best before’ or ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

If you think someone else may have taken the medicine by accident, contact your doctor straight away.

Liquid medicine comes in several different strengths. Make a note of which one you usually have, and check that you have been given the right one each time.

Where should I keep this medicine?

  • Keep the medicine in a cupboard, away from heat and direct sunlight.
  • It does not need to be kept in the fridge.
  • Make sure that children cannot see or reach the medicine.
  • Keep the medicine in the container it came in.

Who to contact for more information?

Your child’s doctor, pharmacist or nurse will be able to give you more information about Spironolactone and about other medicines used to treat heart failure.

England: NHS 111

Tel 111

Scotland: NHS 24

Northern Ireland: NI Direct

Wales: NHS Direct

Tel 111 (free) or 0845 46 47 (2p per minute)

Children’s Heart Federation

0300 561 0065

Copyright disclaimer

Version [2]. © NPPG, RCPCH and WellChild, all rights reserved. Review by January 2017.

The primary source for the information in this leaflet is the British National Formulary for Children. For details on any other sources used for this leaflet, please contact us through our website,

We take great care to make sure that the information in this leaflet is correct and up-to-date. However, medicines can be used in different ways for different patients. It is important that you ask the advice of your doctor or pharmacist if you are not sure about something. This leaflet is about the use of these medicines in the UK, and may not apply to other countries. The Royal College of Paediatrics and Child Health (RCPCH), the Neonatal and Paediatric Pharmacists Group (NPPG), WellChild and the contributors and editors cannot be held responsible for the accuracy of information, omissions of information, or any actions that may be taken as a consequence of reading this leaflet.