Mebendazole (Ovex)
NHS information about the medicine mebendazole, including what it's used for, who can take it, how to take it and side effects.
What mebendazole is for
Mebendazole is used to treat some types of worm infection, such as:
- threadworms (pinworms)
- roundworms
- whipworms
- hookworms
You can buy it from pharmacies to treat threadworms in adults and children aged 2 years or older.
It's only available with a prescription for other worm infections and for children aged from 6 months to 2 years.
Find out about worms in humans.
How to take mebendazole
Mebendazole comes as chewable tablets or a liquid you swallow.
How much you need to take and for how long depends on what type of worm infection you have and whether your symptoms come back.
For threadworm infections, you take a one-off dose. If your symptoms come back, you may need to take another dose 2 weeks later.
For hookworm, whipworm or roundworm infections, you need to take it twice a day, ideally 10 to 12 hours apart, for 3 days.
Always check the packet or leaflet that comes with your medicine. Ask a pharmacist or doctor for advice if you're not sure how to take it or have any problems taking it.
When taking mebendazole:
- chew, crush or swallow the tablet whole with a drink of water (always crush the tablet for children)
- for liquid mebendazole, shake the bottle well and use the spoon or cup that comes with it to make sure you measure the correct dose
Speak to a doctor if your symptoms have not started to improve after a few days of using mebendazole.
Side effects of mebendazole
Like all medicines, mebendazole can cause side effects, although not everyone gets them.
Side effects of mebendazole include:
- stomach pain or discomfort
- farting
- diarrhoea
Mebendazole should not affect your ability to drive, ride a bike or use machinery.
More about side effects
These are not all the side effects of mebendazole.
For a full list, see the leaflet that came with your medicine or search for your medicine leaflet on the electronic medicines compendium website.
You can report any side effects you get on the Yellow Card website
Who can and cannot take mebendazole
Most adults and children aged 2 years or over can take mebendazole. Children aged 6 months to 2 years may be able to take it if prescribed by a doctor.
Mebendazole is not suitable for some people. For example, it may not be suitable if:
- you've had an allergic reaction or serious side effect from mebendazole or a similar medicine, such as albendazole or ivermectin
Check the packet or leaflet that comes with your medicine to see if it's suitable for you. Speak to a pharmacist or doctor if you're not sure if you can take or use it.
Breastfeeding and mebendazole
Speak to a pharmacist or doctor if you're breastfeeding.
Mebendazole can often be used while breastfeeding, but it's best to check because the medicine can pass into your breast milk in small amounts.
If you're taking mebendazole while breastfeeding, speak to a healthcare professional if you have any concerns about your baby.
Pregnancy and mebendazole
Speak to a doctor or pharmacist before taking mebendazole if you're pregnant or think you might be pregnant.
Mebendazole can be used in pregnancy if the benefits outweigh the risks to your baby. A doctor may suggest trying hygiene measures, such as washing hands regularly and keeping fingernails short, to treat the infection first, particularly in early pregnancy.
Taking mebendazole with other medicines, food and drink
There are some medicines, remedies and supplements that may not mix well with mebendazole.
This includes:
- metronidazole, a type of antibiotic
- cimetidine, a medicine used lower the amount of stomach acid
Check the packet or leaflet that comes with your medicine to see if it's suitable for you. Speak to a pharmacist or doctor if you're not sure you can take it.
Food, drink and alcohol with mebendazole
You can eat and drink as normal while taking mebendazole.
Find out more about your medicine
To find out more about your medicine, you can:
- check the leaflet that comes with it
- search for your medicine leaflet on the electronic medicines compendium website
- find out more about mebendazole on the Medicines for Children website
- speak to a pharmacist or doctor for advice
