What the medicine is for
Ovex (Mebendazole) is a medicine which is used to treat threadworm (sometimes known as pinworm) infections of the gut. The tablet contains mebendazole, which is one of a group of medicines called ‘anthelmintics’.
This medicine is for use in adults and children aged over 2 years.
Before taking this medicine
This medicine is suitable for most adults and children, but a few people should not use it. If you are in any doubt, talk to your doctor or pharmacist.
Don’t use this medicine.
- If you have ever had a bad reaction to any of the ingredients.
- If it is for a child under 2 years.
- If you are pregnant or think you are pregnant.
- If any of these apply to you, get advice from a doctor or pharmacist without using Ovex [Mebendazole].
Talk to your doctor or pharmacist.
If you are taking any other medicines, including:
- Metronidazole (a drug used to treat bacterial and protozoan infections] as a serious skin reaction can rarely occur.
- Cimetidine (a medicine used to treat excess stomach acidity).
If you are not sure about any of the medicines you are taking, show the bottle or pack to your pharmacist.
If any of the bullet points apply to you now or in the past, talk to a doctor or pharmacist.
If you are pregnant or breast-feeding
Do not take this medicine if you are pregnant. Ask your doctor or pharmacist for advice before taking this medicine if you are breastfeeding.
Special warnings about this medicine
Since threadworms can spread very easily, it is strongly recommended that all the family (except pregnant, breast-feeding women or children under 2) are treated at the same time and that suitable hygiene precautions are followed to prevent re-infection (see Section 7 of this leaflet for more advice).
How to take this medicine
- Check the table that follows to see how much medicine to take.
- This medicine is a single-tablet dose. Do not take more than the stated dose shown below.
- For oral use only.
- The tablet may be either chewed or swallowed whole. Crush the tablet before giving it to a young child.
- Always supervise a child if they are taking this medicine.
Children under 2 years old
This medicine is not recommended for children aged under 2 years old.
Adults and children aged 2 years and older
| Age | Dose |
| Adults and children aged 2 years and over. | Take one tablet per family member. |
| If symptoms do not disappear within a few days, speak to your doctor. If you are re-infected your pharmacist may recommend that a second tablet is taken after two weeks. Mebendazole cost… | |
lf anyone takes too much
If anyone takes more than one Ovex (Mebendazole) tablet, contact a doctor or your nearest Accident & Emergency department (Casualty) taking this leaflet and pack with you as soon as possible.
Possible side-effects
Ovex (Vermox) can have side-effects, like all medicines, although these don’t affect everyone and are usually mild.
If you experience any of the following, stop using the medicine and seek immediate medical help:
Very rarely: less than 1 in 10,000 people are affected
- Convulsions (seizure/fit) in infants.
- Allergic reactions including unexplained wheezing, shortness of breath, including passing out.
- Skin rashes (which may be severe and include blistering or peeling of the skin] and itching, and may be accompanied by a high temperature.
If you experience any of the following, stop using the medicine and talk to your doctor:
Very rarely: less than 1 in 10,000 people are affected
- Itchiness, hives or swelling.
- Stomach pain or diarrhoea.
Other effects which may occur include:
- Inflammation of the kidneys or liver or abnormal liver function. Reduction in white blood cells (which reduces the body’s defences against infections).
If you experience any side-effects not included in this leaflet or are not sure about anything, talk to your doctor or pharmacist.
Storing this medicine
Keep the product out of the reach and sight of children.
Do not use your medicine after the date shown as expiry on the packaging. There are no special storage conditions.
Further information
What’s in this medicine?
The active ingredient in Ovex is: Mebendazole 100 mg per tablet.
Other ingredients are: Microcrystalline cellulose, sodium starch glycollate, talc, maize starch, sodium saccharin, magnesium stearate, cottonseed oil -hydrogenated, orange flavour, colloidal anhydrous silica, sodium lauryl sulphate, orange yellow S (El 1 0).
What the medicine looks like
Ovex is a pale orange tablet.
Further advice regarding threadworms
What are threadworms?
Threadworms (Enterobius vermicularis) are tiny white parasitic worms that live in the bowel. They are approximately half an inch long and resemble threads of white cotton – hence the name threadworms.
How common are threadworms?
Threadworms are extremely common, especially in children. It is estimated that up to 40% of children under ten years in the UK may be affected at any one time. Once a child has threadworms, it is very easy for the rest of the family to get them.
How do they spread?
Threadworms spread by producing large numbers of tiny eggs. These eggs are so small that they cannot be seen with the naked eye. When swallowed, the eggs pass into the bowel where they hatch into worms. When mature, the female threadworm lays her eggs at night around the anal area, which causes an “itchy bottom”. The resulting irritation can cause intense scratching, which may lead to further infections if the skin becomes sore or broken. Scratching also allows transfer of the eggs to the fingers and nails. Eggs can then be easily transferred to the mouth by finger sucking or nail biting, causing re-infection, and spread to other members of the family by direct contact or via food, towels and bed linen etc.
Threadworm eggs are present in house dust; they stick to clothing, carpets, towels and bed linen; they can also be picked up in garden soil, or on unwashed vegetables and salads. Because the eggs are so small and so widespread, it is very easy for them to be swallowed.
Lifecycle of threadworms 2 – 6 weeks
- Scratching the bottom transfers eggs to fingers and from there back to the mouth or to others either by direct contact or via food, bed linen etc.
- Eggs swallowed.
- Female worms migrate to the anal area to lay eggs at night.
Are they harmful?
Threadworms do not cause serious damage but they are an irritating problem. Besides the intense itching, which can be distressing and embarrassing for the sufferer, they can also lead to disturbed sleep, tummy aches, irritable crying, loss of appetite or an unusually large appetite. Sometimes, threadworms can be transferred to the vagina and urinary passage. This can result in vaginal irritation and discharge, symptoms of cystitis or bed wetting.
Who gets threadworms?
Anyone, although they are more common in children. It does not mean that your family or your home are not clean. Because threadworms are passed on very easily it is a wise precaution to treat everyone in the family at the same time.
How can you tell if someone has threadworms?
The most obvious sign of threadworms is intense itching in the anal area, especially at night, although this does not affect everyone. If your children frequently scratch their bottoms, suffer from disturbed sleep or become irritable, it is worth checking their motions and the anal area for tiny white threads. If one member of the family has threadworms, the rest of the family may already have picked up the infection, even if they do not have obvious symptoms. Important note: Threadworms only affect humans, they do not affect pets.
General advice
To ensure that you and your family do not infect others or re-infect yourselves, you should also follow the hygiene measures listed below for at least six weeks:
- Keep nails short.
- Discourage nail biting or finger sucking.
- Wear pyjamas or underclothes in bed.
- In the mornings, wash thoroughly around the bottom.
- Provide a towel for the exclusive use of each member of the household.
- Change clothes regularly.
- Regularly wash and iron bed linen.
- Thoroughly wash hands and nails after using the toilet and before each meal.
Do you need to keep your children off school?
No. As long as the children are treated and the general hygiene measures outlined above are followed, there is no reason to keep them off school.
How can you stop the problem coming back?
Threadworms are easily treated but unless the following precautions are taken the problem may recur:
Follow the general advice above.
Make sure everyone in the family is treated at the same time.