Cefalexin for bacterial infections


This leaflet is about the use of cefalexin for the treatment of bacterial
infections.

Information Standard quality markThis leaflet has been written specifically about the use of this medicine in children. The information may differ from that provided by the manufacturer. Please read this leaflet carefully. Keep it somewhere safe so that you can read it again.

If your child has ever had a reaction to any antibiotic, check with your doctor that your child can have cefalexin before giving it.

Name of drug

Cefalexin 
Brand names: Ceporex®, Keflex®

Why is it important for my child to take this medicine?

It is important that your child takes this medicine in the way that your doctor has told you to so that it kills the bacteria and gets rid of the infection.

What is cefalexin available as?

  • Tablets: 250 mg, 500 mg
  • Capsules: 250 mg, 500 mg
  • Liquid medicine (suspension): 125 mg in 5ml or 250 mg in 5mL

When should I give cefalexin?

Cefalexin is usually given three times a day. However, your doctor may have told you to give it twice or four times a day. 

  • Twice a day: this should be once in the morning and once in the evening. Ideally, these times are 10–12 hours apart, for example between 7 and 8 am, and between 7 and 8 pm.
  • Three times each day: this should be once in the morning, once in the early afternoon and once in the evening. Ideally, these times are at least 6 hours apart, for example 8 am, 2 pm and 8 pm. 
  • Four times each day: this should be once in the morning, at around midday, once in the early afternoon and once in the evening. Ideally, these times are about 4 hours apart, for example 8 am, midday, 4 pm and 8 pm. 

Give the medicine at about the same times 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 cefalexin (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 it?

Tablets should be swallowed with a glass of water, milk or juice. Your child should not chew the tablet. 


Capsules should be swallowed with a glass of water, milk or juice. Your child should not chew the capsule. 


Liquid medicine: Measure out the right amount using a medicine spoon or oral syringe. 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? 

Your child should start to get better after taking the medicine for 2 or 3 days. It is important that your child has the whole course of medicine that has been prescribed. Do not stop early.

If your child has a fever (temperature above 38°C) that does not get better, or they become more unwell, contact your doctor.

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of cefalexin, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of cefalexin, 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 2 hours after you should have given a dose, give the missed dose.If you remember after this time, do not give the missed dose. Wait until the next normal dose. Try to make sure that there is about 4 hours between doses.

What if I give too much? 

Cefalexin is normally a safe drug. It is unlikely to cause any problems if you give an extra dose by mistake. If you are worried that you may have given your child too much cefalexin, contact your doctor or NHS Direct (0845 4647). Have the medicine container or packaging with you if you telephone for advice.

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 that you must do something about

If your child is short of breath or is wheezing, or their face, lips or tongue start to swell, or they develop a rash, they may be allergic to cefalexin. Take your child to hospital or call an ambulance straight away. 

Important things to know about taking antibiotics

  • It is important that your child completes the course of antibiotic. This means that they must take the medicine for the number of days that the doctor has told you to, or until all the medicine has been taken. If you stop giving the antibiotic too soon, the troublesome bacteria that are left will start to multiply again, and may cause another infection. There is also a risk that these bacteria will be ‘resistant’ to (will not be killed by) the first antibiotic. This means that it might not work next time, and your child might need a different antibiotic.
  • Children are sometimes sick (vomit) or get diarrhoea when taking antibiotics. Encourage them to drink water to replace the fluid they have lost. If it is severe or your child is drowsy, contact your doctor.
  • Do not give your child any medicine to stop the diarrhoea unless your doctor has told you to, as this can make things worse.
  • Try to give the medicine at about the same times each day, to help you remember, and to make sure that there is the right amount of medicine in your child’s body to kill the bacteria.
  • Only give this medicine to your child for their current infection.
  • Never save medicine for future illnesses. Throw away any unused medicine or return it to the pharmacist.
  • Only give the antibiotic to the child for whom it was prescribed. 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.

Other side-effects you need to know about

  • Your child may have diarrhoea, stomach pains, feel sick or be sick (vomit) when they first start to take cefalexin. The box above gives advice on what to do.
  • Contact your doctor if your child has diarrhoea that goes on for more than 4 days or if it is severe and watery, or contains blood.
  • You may see white patches inside your child’s mouth and throat, and girls may get itching or soreness around the vagina. This is caused by a fungal infection called thrush. If you think your child may have thrush, contact your doctor or pharmacist for advice. 

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

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Check with your doctor or pharmacist before giving any other medicines to your child. This includes herbal or complementary medicines.

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

If your child has ever had a reaction to any antibiotic, tell your doctor or pharmacist before giving cefalexin. 

Where I should keep this medicine? 

  • Keep the medicines in a cupboard, away from heat and direct sunlight. 

You may need to keep liquid medicine in the fridge - check the instructions on the bottle. Make sure that 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 cefalexin.


You can also get useful information from:


Publication Date

9/9/2011

Copyright Disclaimer

Version 1, July 2011. © NPPG, RCPCH and WellChild 2011, all rights reserved. Reviewed by: July 2013. 

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, www.medicinesforchildren.org.uk.

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.