Roundworm infections can be successfully treated using one of a number of medicines.

The three main medicines are:

• mebendazole
• piperazine
• albendazole

These are described below.

Mebendazole

Mebendazole is recommended for treating roundworm infections in adults and children over the age of one.

It works by stopping the roundworms using glucose (sugar). Without glucose, the cells of the roundworms lose their energy supply and quickly die.

A three-day course of mebendazole is usually recommended. This involves taking one tablet twice a day.

Stomach pain is the most common side effect of mebendazole. Less common side effects include:

• skin rash
• diarrhoea 
• flatulence (excessive wind)

Piperazine

Piperazine is recommended for babies aged 3-11 months. It's available as a powder that you dissolve in water. Most children only require a single dose.

Side effects of piperazine can include:

• stomach (abdominal) pain
• nausea and vomiting 
• colic (excessive, frequent crying) 
• diarrhoea

These side effects should pass quickly once the medicine works its way out of the body.

If your child is less than three months of age, delaying treatment until they reach three months may be recommended.

Albendazole

Albendazole is commonly used in tropical countries, but is currently unlicensed for use in the UK.

This means the medicine's manufacturer hasn't applied for a license for albendazole to be used to treat roundworm in the UK. However, it's been extensively studied in countries where roundworm is common, and has been shown to be safe and effective.

Pregnancy

While there's no firm evidence to suggest that any of the medications above can cause birth defects, they're not usually recommended during pregnancy.

Roundworms can occasionally cause troublesome symptoms, but they don't usually pose a threat to your unborn child.