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Cefalexin for bacterial infections

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Cefalexin for bacterial infections

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

Information-Standard-logoThis leaflet has been written for parents and carers about how to use this medicine in children. Our information sometimes differs from that provided by the manufacturers, because their information is usually aimed at adult patients. Please read this leafl et 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 (kef-a-LEX-in)
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 harmful 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, 250 mg or 500 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, which is based on your child’s age and severity of the infection.

  • 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: Shake the medicine well.
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. If your child has a fever (temperature above 38°C), that still does not get better, or they become more unwell, contact your doctor.
It is important that your child has the whole course of medicine that has been prescribed. Do not stop early.

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.

If your child is sick again, seek advice from your GP, 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 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? 

You are unlikely to do harm if you give an extra dose of cefalexin by mistake. If you are concerned that you may have given too much, contact your doctor or local NHS services (111 in England and Scotland; 0845 4647 in Wales). Have the medicine 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

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.

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 http://www.mhra.gov.uk/yellowcard.

Important things to know about taking antibiotics

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

  • 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 of the medicine has been taken. If you stop giving the antibiotic too soon, the 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 the first antibiotic. This means that it might not work next time, and your child might need a different antibiotic, which might not work as well or cause more side-effects.
  • Children are sometimes sick (vomit) or get diarrhoea when taking antibiotics. Encourage them to drink water to replace the fluid they have lost.
  • Do not give your child any medicine to stop the diarrhoea unless your doctor has told you to.
  • 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. Give old or unused antibiotics to your pharmacist to dispose of.
  • 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.
  • Antibiotics only kill bacteria; they do not kill viruses. This means that they do not work against colds, sore throats, flu or other infections that are caused by viruses. Your doctor will not prescribe antibiotics for these illnesses.

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 should I 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: 
26/06/2015

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