Mebendazole for worm infections

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Mebendazole for worm infections

This leaflet is about the use of mebendazole for worm infections.
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This leaflet is 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 adults. Please read this leaflet carefully. Keep it somewhere safe so that you can read it again

Name of medicine

Brand names:
Vermox®, Ovex™

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

Children commonly pick up infections with worms that live in the intestines. It is important to take mebendazole to kill these worms. You will also need to take extra steps to prevent re-infection, described later in this leaflet.

What is mebendazole available as?

  • Tablets: 100 mg
  • Liquid medicine (suspension): 100 mg in 5 mL

When should I give mebendazole?

Mebendazole may be given either as a single dose or twice each day for 3 days, depending on the type of worm your child is infected with. Your doctor will tell you how often to give it.

  • Once: this can be at any time of 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 some time between 7am and 8 am, and between 7pm and 8 pm.

If you give a single dose of mebendazole you may need another single dose two weeks later, to prevent re-infection. Your doctor will give you advice about this.

How much should I give?

Your doctor will work out the amount of mebendazole (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?

TabletsTablets may be swallowed with a glass of water, milk or juice. They can also be chewed before swallowing. Ideally your child should drink a glass of water, milk or juice after chewing and swallowing the tablet.

Liquid medicine with oral syringeLiquid medicine: Shake the bottle well and measure out the right amount using an oral syringe or 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 should start to work straight away but it may take several days to kill all the worms. It is important that your child takes the whole course of the medicine that has been prescribed. Do not stop early.

If you gave a single dose of mebendazole your child may need another single dose two weeks later, to prevent re-infection. Your doctor will give you advice about this.

What if my child is sick (vomits)?

  • If your child is sick less than 30 minutes after having a dose of mebendazole, give them the same dose again.
  • If your child is sick more than 30 minutes after having a dose of mebendazole, 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 family doctor, pharmacist or hospital. 

What if I forget to give it?

If you are giving the medicine 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 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. Just give the next dose as usual. Make sure you give all of the doses to finish the course of medicine.

Never give a double dose of mebendazole.

What if I give too much?

You are unlikely to do harm if you give an extra dose of mebendazole by mistake. If you are concerned that you may have given too much, contact your doctor or local NHS services (details at end of leaflet).  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 you must do something about

If your child gets blistering of their skin, mouth, eyes or genitals, take them to hospital or call an ambulance straight away.

Very rarely, mebendazole can cause seizures (convulsions or fits). If your child has a seizure, telephone for an ambulance. Do not restrain your child, but try to make sure they cannot hurt themselves (e.g. put a cushion under their head, place them on their side and move them away from furniture).

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 your child’s liver.

Other side-effects you need to know about
  • Your child may get stomach pain, diarrhoea or flatulence (wind). If you are worried 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 www.mhra.gov.uk/yellowcard

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

  • You can give your child medicines that contain paracetamol or ibuprofen, unless your doctor has told you not to.
  • Mebendazole should not be taken with some medicines. Tell your doctor and pharmacist about any other medicines your child is taking before giving mebendazole.
  • 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 must take the medicine for the number of days that your doctor has told you to, or until all the medicine has been taken. If you stop giving the medicine too soon the worm infection may come back. 
  • Your doctor will probably recommend that all members of the family should be treated on the same day, whether or not they have any symptoms of infection (unless they are pregnant).  
  • Mebendazole should not be used for children under the age of 2 years.

Mebendazole may harm an unborn baby. If your daughter thinks that she may be pregnant she must talk to her doctor before taking mebendazole.

Preventing re-infection

  • Worm infections are easily spread between members of a family, and it is easy to get re-infected. 
  • The worms lay eggs around the anus at night. These eggs can be transferred back to the mouth, causing re-infection.
  • All members of the family must therefore take extra care with hygiene for at least 6 weeks after the infection.
  • Wash hands thoroughly, including under the finger nails, before preparing food or eating and after using the toilet. Wear underwear in bed and wash the bedding and underwear regularly. 
  • Have a bath or shower as soon as you get up in the morning. Do not share towels.

General advice about medicines

  • Try to give medicines at about the same times each day, to help you remember.
  • If you are not sure a medicine is working, contact your doctor but continue to give the medicine as usual in the meantime. Do not give extra doses, as you may do harm.
  • If you think someone else may have taken the medicine by accident, contact your doctor.
  • Make sure that the medicine you have at home has not reached the ‘use by’ date on the packaging. Give old medicines to your pharmacist to dispose of.

Where I should 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 doctor, pharmacist or nurse will be able to give you more information about mebendazole and about other medicines used to treat worm infections.

You can also get useful information from: 
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