About loperamide

Loperamide is a medicine to treat diarrhoea (runny poo). It can help with short-term diarrhoea or irritable bowel syndrome (IBS).

Loperamide is also used for recurring or longer lasting diarrhoea from bowel conditions such as Crohn's disease, ulcerative colitis and short bowel syndrome.

If you have a colostomy (an opening in your stomach to collect poo from your body), loperamide can make your poo thicker. It does this by slowing down your food as it passes through your gut.

You can buy loperamide from pharmacies and supermarkets. It is also available on prescription for treating some bowel conditions.

It comes as tablets, including tablets that melt on your tongue, capsules and a liquid. The liquid is only available on prescription. The tablets that melt are called Imodium Instants or Imodium Instant Melts

Loperamide is also available combined with simeticone. Simeticone is used to treat farting (flatulence or wind). Taking these medicines together helps if you have diarrhoea with painful stomach cramps and bloating.

Loperamide mixed with simeticone is known by the brand names Imodium Plus Caplets and Imodium Plus Comfort Tablets.

Key facts

Who can and cannot take loperamide

You can buy loperamide from pharmacies and supermarkets or you can get it on prescription.

Loperamide is available to buy without a prescription for:

It's available on prescription only for:

Younger children

Only give loperamide to children aged 11 years or under if their doctor prescribes it.

Loperamide is not suitable for some people.

Do not take loperamide if you:

Check with your doctor before taking loperamide if you:

If you have diarrhoea and IBS, talk to your doctor before taking loperamide if you:

How and when to take loperamide

If you've bought loperamide from a pharmacy or shop, follow the instructions that come with the packet.

If your doctor has prescribed loperamide for you or your child, follow their instructions about how and when to take it.

How to take it

You can take loperamide with or without food.

Capsules and tablets: swallow these whole, with a drink of water.

Tablets that melt in your mouth: put the tablet on your tongue and let it melt in your saliva. You can then swallow it without a drink. Do not chew it.

Liquid: this comes with a measuring cup, plastic syringe or spoon to help you measure the right dose. If you do not have one, ask your pharmacist. Do not use a kitchen teaspoon as it will not give the right amount of medicine.

Dosage and strength

Loperamide comes as:

The recommended dose depends on the type of diarrhoea you have and your age.

Adults (over 18), with short-term diarrhoea or IBS

The usual starting dose is:

Stop taking loperamide as soon as your symptoms settle down.

The recommended maximum dose in 24 hours is:

Do not take loperamide for more than 48 hours without talking to a doctor.

Adults (over 18) with long-lasting or recurring diarrhoea

Most cases of diarrhoea get better in 5 to 7 days. If your diarrhoea does not stop in 7 days, talk to your doctor. It is important to understand the causes and to treat any complications, for instance dehydration.

If your doctor prescribes loperamide for long-lasting diarrhoea, they will tell you how much to take. The usual starting dose is:

Your doctor will adjust your dose according to your symptoms and how well loperamide is working, up to a maximum of:

Once you're on the right dose, your doctor will usually recommend dividing your daily dose, so you take half in the morning and half in the afternoon or evening.

Occasionally patients with a colostomy (stoma) need a higher dose. Only take a higher dose if your doctor tells you to.

Children's doses

Do not give loperamide to children under 12 years old unless their doctor prescribes it.

If a doctor prescribes loperamide for your child, they will use their weight or age to work out the right dose. The dose also depends on their symptoms.

What if I forget to take it?

If you miss a dose of loperamide, do not worry. Just take a dose after you next go to the toilet and have a runny poo.

Do not take a double dose to make up for the one you forgot.

What if I take too much?

Do not take more than the recommended amount.

If you take 1 extra dose of loperamide as a one-off, it's unlikely to harm you. But taking higher doses can cause serious heart problems. The signs include having a fast or irregular heartbeat.

Contact 111 for advice now if:

  • you take 2 extra doses of loperamide or more
  • you take more than the recommended dose and get a fast or irregular heartbeat

Go to 111.nhs.uk or call 111

If you need advice for a child under the age of 5 years, call 111.

Side effects

Like all medicines, loperamide can cause side effects, but many people have no side effects or only minor ones.

Common side effects

These common side effects happen in more than 1 in 100 people.

Talk to your doctor or pharmacist if these side effects bother you or do not go away:

Serious side effects

It's rare to have a serious side effect with loperamide.

Tell a doctor straight away if you:

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to loperamide.

These are not all the side effects of loperamide. For a full list, see the leaflet inside your medicines packet.

How to cope with side effects of loperamide

What to do about:

Pregnancy and breastfeeding

Loperamide in pregnancy

Loperamide is not usually recommended in pregnancy. This is because there is not enough information to say whether it is safe or not.

If you're pregnant, talk to your doctor before taking loperamide.

They'll be able to advise you about the benefits and possible harms of taking it. This will depend on how many weeks pregnant you are and why you need to take it.

If you’re trying to get pregnant, talk to your doctor if you take loperamide on prescription as part of ongoing treatment for a bowel condition.

Loperamide and breastfeeding

It is OK to take loperamide for a couple of days while you're breastfeeding. Hardly any loperamide passes into breast milk, and so it will not affect your baby.

If you notice that your baby isn’t feeding as well as usual, seems unusually sleepy, or if you have any other concerns about your baby, then talk to your doctor, midwife or health visitor.

For more information about how taking this medicine can affect you and your baby, read this leaflet about loperamide on the Best Use of Medicines in Pregnancy (BUMPs) website.

Cautions with other medicines

There are some medicines that can affect the way loperamide works.

Check with a pharmacist or doctor if you're taking:

Speak to your doctor if your diarrhoea is very severe and you take metformin for diabetes, or medicines for high blood pressure or heart failure. Your doctor may tell you to stop taking these medicines for a few days until your diarrhoea is better.

Mixing loperamide with herbal remedies or supplements

There's very little information about taking herbal remedies and supplements with loperamide.

Common questions about loperamide

How does loperamide work? How long does loperamide take to work? How long will I take it for? Why is it important not to take loperamide for longer than recommended? Is it safe to take for a long time? Can I take loperamide to prevent diarrhoea? Can I drink alcohol with it? Is there any food or drink I need to avoid? Can I drive or ride a bike? Can I take loperamide with painkillers? Are there any other treatments that could help diarrhoea?