Lomper (Mebendazole) in Spain: What It Treats and Whether You Need a Prescription

Lomper is the Spanish brand of mebendazole, a worm medicine. It treats threadworms (pinworms) and some other gut worms. In Spain both forms, the liquid and the tablets, need a prescription. This guide is by Dr. Pedro Yelamo Vera, an English-speaking GP licensed in Spain (Colegiado No. 484814280) who sees patients by video in English and Spanish.

What is Lomper used for?

Lomper is used to clear worms that live in the gut. Its Spanish product information lists these infections, alone or mixed:

• Threadworms, called pinworms in the US and oxiuros in Spain. These tiny white worms cause an itchy bottom at night.
• Roundworms (ascariasis).
• Whipworms (trichuriasis).
• Hookworms.

It does not treat scabies, head lice, fungal infections or bacteria. For the signs of threadworms in a child, see our guide to threadworms in children.

What is Lomper called in the UK and the US?

The medicine inside Lomper is mebendazole. Only the brand names change:

• Spain: Lomper (mebendazol).
• UK: Ovex, and also Vermox.
• US: Emverm and Vermox.

So a box of Ovex or Vermox from home holds the same medicine as Lomper.

Do you need a prescription for Lomper in Spain?

Yes. On CIMA, the database of the Spanish medicines agency (AEMPS), both Lomper packs are prescription-only. That covers Lomper liquid and Lomper tablets. No mebendazole pack is sold without a prescription in Spain.

The pharmacy will ask for a Spanish prescription. Spanish pharmacies ask for a prescription from a doctor licensed in Spain, so a foreign prescription is normally refused. One threadworm medicine is sold without a prescription in Spain: pyrantel, as Trilombrin. Ask the pharmacist if it suits you. Our table of which medicines need a prescription in Spain lists many more.

How are the UK and US rules different?

The rules differ from country to country:

• UK: pharmacies sell mebendazole for threadworms without a prescription. You must tell the pharmacist about a child under 2, or if you are pregnant or breastfeeding.
• US: mebendazole needs a doctor's prescription.
• Spain: it always needs a prescription.

Lomper liquid or tablets: which form?

Both forms hold the same medicine and treat the same worms. In Spain there are two packs:

• Lomper 20 mg/ml suspensión oral: a yellow liquid with a fruit flavour. People often call it Lomper syrup (jarabe). Shake it before use.
• Lomper 100 mg comprimidos: orange tablets with an orange flavour.

The liquid is advised for anyone who cannot swallow tablets, to lower the risk of choking. You can take either form with or without food. How much to take, and for how long, is set by the prescription or the leaflet.

Some ingredients matter for a few people:

• The liquid contains sugar (sucrose). People with rare sugar intolerances, such as hereditary fructose intolerance, should not take it.
• The liquid contains parabens, which can cause allergic reactions.
• The tablets contain the dye E-110 and sulfites. Rarely, these cause allergic reactions.

Can adults take Lomper?

Yes. Lomper is approved for adults, teenagers and children aged 2 and over. Adults often take it on the same day as their children, even with no symptoms.

From what age can children take Lomper?

Children can take Lomper from age 2. Below that age, the Spanish product information is strict:

• Under 1 year: it must not be used. There is not enough safety data. Very rarely, fits (seizures) have been reported in young children.
• Age 1 to 2: not advised. Only a doctor can decide, if the benefit outweighs the risk.
• Age 2 and over: it can be used with a prescription. The liquid is easier for young children.

Why does the whole household take it at once?

Because threadworm eggs spread very easily between people who live together. Many people carry worms with no symptoms. If only the child with the itch is treated, others can pass the eggs back. So doctors often treat everyone at home on the same day.

The medicine kills the worms but not the eggs. So a second round is often given later, to clear worms that hatch after the first. Your prescription says when.

Is the medicine enough on its own?

Not always: without good hygiene, eggs can infect the family again. During treatment, these steps help:

• Wash hands with soap after the toilet, after changing nappies and before eating.
• Keep nails short and clean. Try not to bite them.
• Shower in the morning and wear clean underwear each day.
• Wash sheets, nightwear and towels often. Do not shake them first.
• Do not share towels. Clean the toilet seat every day.

Can you take Lomper when pregnant or breastfeeding?

Only if a doctor checks first. Do not take it on your own. In animal studies, mebendazole harmed the unborn young. So the doctor must weigh the risks, above all in the first three months. A small amount passes into breast milk, so a doctor also decides when you breastfeed. In pregnancy, a doctor may suggest hygiene steps alone first.

What are the side effects of Lomper?

The most common side effect is tummy pain. Others include:

• Uncommon: tummy upset, diarrhoea, wind, feeling sick, being sick and a rash. Pain and diarrhoea are more likely when many worms pass out.
• Rare: dizziness.
• Very rare: allergic reactions, hives, swelling of the face, fits, liver problems, low white blood cells, hair loss, kidney inflammation and severe skin reactions with blisters.

Lomper does not affect your ability to drive.

Which medicines should not be taken with Lomper?

Do not take it with metronidazole, an antibiotic. This mix has been linked to severe skin reactions (Stevens-Johnson syndrome). Cimetidine, a stomach medicine, can change how the body clears mebendazole. Always tell the doctor about all your medicines.

When to see a doctor

• The child is under 2.
• You are pregnant or breastfeeding.
• Symptoms go on after treatment and hygiene steps.
• There is bad tummy pain, blood in the poo or weight loss.
• You have travelled and think it may be a different worm.
• You take metronidazole or other medicines.

When to call 112

• Trouble breathing, or swelling of the face, lips or tongue.
• A fit (seizure).
• Blisters or peeling skin, above all with fever or sores in the mouth or eyes.

If any of these happen, stop Lomper and get urgent help.

Frequently asked questions about Lomper

Getting a medical assessment

If you are not sure whether Lomper is right for you or your family, you can book a video consultation with Dr. Pedro Yelamo Vera, a physician registered in Spain. You can also read about threadworms in children and how the urgent care video visit works. A prescription is never guaranteed: it is issued only where clinically appropriate after a genuine evaluation, as a private electronic prescription under Spanish law. This service is for urgent, non-emergency care. In an emergency, call 112.

This guide is general information. It does not replace the package leaflet or the advice of your doctor or pharmacist.