Potassium chloride for potassium depletion

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.

Name of medicine

Potassium chloride

Brand names: Sando-K (effervescent tablets), Kay-Cee-L (liquid)

Modified-release tablets: Slow-K

Why is it important for my child to take Potassium chloride?

Potassium is a mineral, which all cells in the body need to function properly. Low potassium levels can mean that important organs in the body like the heart, nerves and muscles do not function properly.

Your child may have low potassium levels because they are not taking in enough in their diet; they are losing too much because of diarrhoea, excessive sweating or dehydration; or they have a problem with their kidneys. Potassium chloride will help to increase the levels of potassium in your child’s blood.

What is Potassium chloride available as?

  • Effervescent (fizzy) tablets: Each tablet contains 470 mg of potassium (12 mmol) and 285 mg ofchloride (8 mmol)
  • Modified-release (Slow-K) tablets: 600 mg(8 mmol each of potassium and chloride)
  • Liquid medicine (syrup): 7.5% potassium chloride (1 mmol/mL each of potassium and chloride)

If you have any concerns or questions, speak with your child’s doctor or pharmacist.

When should I give Potassium chloride

The Potassium chloride 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.

Try to give the medicine(s) at about the same times each day, to help you remember.

How much should I give?

Your doctor will work out the amount of Potassium chloride (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 Potassium chloride?

Effervescent (Sando-K) tablets

Dissolve the tablet in a glass of water. You can add squash or juice to hide the taste. Your child should drink it all either straight away or over 30 minutes. Your child should not chew these tablets. You can also crush the tablet and mix it with a small amount of soft food, such as jam. Make sure your
child swallows it straight away, without chewing. Do not give the medicine with milk or yoghurt.

  • Dissolve the tablet(s) in water. Your doctor or pharmacist will have told you how much water to use and how much to give to your child. Make sure your child drinks it all straight away, using a medicine spoon or oral syringe.

Modified-release (Slow-K) tablets

The tablets should be taken with, or just after, a meal. They should be swallowed whole, while standing up, with a glass of water or juice. Your child must not chew, crush or break the tablet. It is essential that it is swallowed with plenty of water or juice.

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?

The medicine will start working within 1–2 days, though you may not see a difference in your child. When the doctor tests their blood, they will notice a change. Continue to give the
medicine to your child during this time. If you are worried about whether it is helping, contact your doctor.

What if my child is sick (vomits)?

If your child is sick less than 30 minutes after having a dose of Potassium chloride, give them the same dose again.

If your child is sick more than 30 minutes after having a dose of Potassium chloride, you do not need to give them another dose. Wait until the next normal dose.

What if I forget to give it?

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 7 am, you can give the missed dose at any time up to 11 am. If you remember after that time, do not give the missed dose. Wait until the next normal dose. You do not need to wake up a sleeping child to give a missed dose.

Never give a double dose of Potassium chloride.

What if I give too much?

If you think you may have given your child too much Potassium chloride, 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 may be dangerous to give too much Potassium chloride.

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 bad stomach pain, brings up (vomits) blood or their stools (poo) are very dark, contact your doctor or take your child to hospital straight away, as they may have an ulcer.

Other side-effects you need to know about

  • Your child may get stomach pain or cramps, and may feel sick (nausea) or be sick (vomit). Giving the medicine with some food or milk may help. These side effects usually wear off after a few days as your child gets used to the medicine. If they are still a problem after one week contact your doctor.

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 Potassium chloride?

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Potassium chloride should not be taken with some medicines. Tell your doctor or pharmacist about any other medicines your child is taking before giving Potassium chloride.
  • 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?

It is important to attend any clinic appointments to ensure that your child is getting the right dose and to monitor if potassium levels are too high or too low – this is critical for the safety of your child.

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.
  • If you feel your child is not improving, do not give extra medicine. Please continue with the regular dose and speak to your doctor.
  • 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.
  • If you think someone else may have taken the medicine by accident, contact your doctor for advice.
  • 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.

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.
  • You may need to keep liquid medicine in the fridge – check the instructions on the bottle. Make sure the medicine does not freeze.
  • 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 doctor, pharmacist or nurse will be able to give you more information about Potassium chloride and about other medicines used to treat potassium depletion.

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)

Copyright disclaimer

Version [1]. © NPPG, RCPCH and WellChild, all rights reserved. Review by August 2019.

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.