Loperamide (Imodium)

1. 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 longer lasting diarrhoea from bowel problems such as Crohn's disease, ulcerative colitis and short bowel syndrome. If you have a colostomy to give you a stoma (an opening in your stomach to collect poo from your body), loperamide can help to slow down your bowel and make your poo thicker.

Loperamide is available on prescription. You can also buy it from pharmacies and supermarkets.

It comes as tablets, capsules and a liquid. You can also get tablets which melt in your mouth. The liquid is only available on prescription.

Loperamide is also available combined with simethicone. Simethicone is used to treat wind. Having the 2 medicines together helps if you have diarrhoea with painful stomach cramps and bloating.

2. Key facts

  • Diarrhoea which starts suddenly usually gets better on its own within 5 to 7 days. If you need immediate, short term relief, taking loperamide can cut down the number of times you go to the toilet and it makes your poo less watery.
  • If you are an adult and you get short term diarrhoea, take 2 tablets or capsules straight away. Then take 1 each time you do a runny poo.
  • Do not give loperamide to children under 12 years old unless their doctor has prescribed it.
  • If you've bought loperamide from a shop or pharmacy, do not take it for more than 48 hours without talking to a doctor.
  • Do not take more than the recommended amount. Too much loperamide can cause serious heart problems (including a fast or irregular heartbeat).
  • Loperamide is also called by the brand names Dioraleze and Imodium. Some supermarkets and pharmacies sell their own brands, usually called 'anti-diarrhoea' or 'diarrhoea relief' capsules. When loperamide comes mixed with simethicone it's called Imodium Plus Caplets and Imodium Plus Comfort Tablets.

3. Who can and can't take loperamide

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

You can buy it without a prescription for:

  • anyone aged 12 and older with short term diarrhoea
  • an adult (over 18 years old) with IBS diarrhoea, provided that your doctor has diagnosed IBS. (If you are not sure whether you have IBS, talk with your doctor.)

You need a prescription for:

  • a child under 12 years old
  • a child aged 12 to 17 years old with IBS or long lasting diarrhoea
  • an adult aged 18 years and older with long lasting diarrhoea

Important

Never give loperamide to children under 12 years old unless their doctor prescribes it.

Loperamide isn't suitable for some people.

Do not take loperamide if you:

  • have severe diarrhoea after taking antibiotics
  • are having a flare-up of an inflammatory bowel condition like ulcerative colitis
  • are constipated or your stomach looks swollen

Check with your doctor before taking loperamide if you:

  • have had an allergic reaction to loperamide or any other medicines in the past
  • have had diarrhoea for more than 48 hours
  • have AIDS and your stomach becomes swollen
  • have liver problems
  • can't digest some sugars (some loperamide products contain the sugar lactose)
  • have blood in your poo and a temperature (more than 38C) - they may be signs that you have dysentery
  • are trying to get pregnant, are already pregnant or you're breastfeeding

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

  • are aged 40 years or over and it's some time since your last IBS attack or your symptoms are different this time
  • have recently had blood in your poo (your poo might be bright red or black)
  • get bad constipation
  • are feeling sick or vomiting
  • have lost your appetite or lost weight
  • have a fever (a high temperature - more than 38C)
  • have trouble peeing or find peeing painful
  • have recently travelled abroad - you may have picked up a stomach bug

4. How and when to take it

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.

Different ways of taking loperamide

Loperamide comes as:

  • tablets and hard or soft capsules (2mg)
  • tablets that dissolve on your tongue (2mg) - these are called Imodium Instants or Imodium Instant Melts
  • a liquid medicine (labelled 1mg/5ml) - the liquid is only available on prescription

The capsules and tablets all contain the same amount of loperamide (2mg) whether you get them on prescription or buy them yourself. They all work as well as each other but some of the products have different labels.

Some supermarkets and pharmacies sell their own versions of loperamide, usually called 'anti-diarrhoea' or 'diarrhoea relief' capsules. Some products have 'IBS' in the name so people realise they can be used for attacks of diarrhoea with IBS. However, they're no different from other brands. People with IBS can also use brands without 'IBS' in the name.

If you're not sure which brand or form of loperamide to get, talk to your pharmacist.

You can also get loperamide combined with simethicone to help if you have painful wind and bloating as well as diarrhoea. This is called Imodium Plus Caplets and Imodium Plus Comfort Tablets.

How to take it

You can take loperamide with or without food.

  • Capsules and tablets - swallow them whole with a drink of water.
  • Tablets which 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 loperamide - this comes with a measuring cup, plastic syringe or spoon to help you measure the right dose. If you don't have one, ask your pharmacist. Do not use a kitchen teaspoon as it will not give the right amount of medicine.

How much should I take?

This depends on the type of diarrhoea you have and your age.

Adults (over 18 years old), including adults with IBS

The usual dose is:

  • capsules or tablets: take 2 capsules or tablets straight away. Then take 1 capsule or tablet after each runny poo.
  • liquid: take 4 spoonfuls (5ml each) straight away. Then take 2 spoonfuls after each runny poo.

Stop taking loperamide as soon as your symptoms settle down.

The recommended maximum daily dose is:

  • 6 capsules or tablets in 24 hours if you bought them from a shop
  • 8 capsules or tablets or 16 spoonfuls of liquid (5ml each) in 24 hours if you bought them from a pharmacy or your doctor prescribed loperamide

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

Adults (over 18 years old) with long lasting diarrhoea

Most cases of diarrhoea get better in 5 to 7 days. If your diarrhoea doesn't 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:

  • 2 to 4 capsules or tablets spread over the day
  • 4 to 8 spoonfuls of liquid loperamide (5ml each) spread over the day

Your doctor will adjust your dose according to your symptoms, up to a maximum of:

  • 8 tablets or capsules in 24 hours
  • 16 spoonfuls of liquid loperamide (5ml each) in 24 hours

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

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

Children

You can give children over 12 years old with short term diarrhoea the same dose as adults. But if they are 12 to 17 years old and have IBS or long lasting diarrhoea, they should only take it if their doctor prescribes it.

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

If a doctor prescribes loperamide for a child under 12 - or for a child aged 12 to 17 years old with IBS or long lasting diarrhoea - they will use your child's weight or age to work out the right dose. The dose also depends on your child's symptoms.

What if I forget to take it?

If you miss a dose of loperamide, don't worry. Just take another 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 an extra dose of loperamide by accident, it's unlikely to harm you. But taking higher doses can cause serious heart problems. The signs include having a fast or irregular heartbeat.

Speak to your pharmacist or doctor if you're worried or take more than 1 extra dose.

5. Side effects

Like all medicines, loperamide can cause side effects in some people 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 don't go away:

  • constipation (difficulty doing a poo)
  • feeling dizzy
  • feeling sick
  • headaches
  • wind

Serious side effects

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

Tell a doctor straight away if you:

  • feel faint or less alert, or if you have passed out
  • are moving in a clumsy, uncoordinated way

Serious allergic reaction

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

Contact a doctor straight away if:

  • you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
  • you're wheezing
  • you get tightness in the chest or throat
  • you have trouble breathing or talking
  • your mouth, face, lips, tongue or throat start swelling

These are warning signs of a serious allergic reaction. A serious allergic reaction is an emergency.

These aren't all the side effects of loperamide. For a full list, see the leaflet inside your medicines packet.

Information:

You can report any suspected side effect to the UK safety scheme.

6. How to cope with side effects

What to do about:

  • constipation - stop taking loperamide. Drink plenty of water. If this doesn't help, talk to your pharmacist or doctor.
  • feeling dizzy - if loperamide makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until you feel better. If you begin to feel dizzy, lie down so that you don't faint, then sit until you feel better. Take care driving or using tools or machines if you get side effects such as dizziness.
  • feeling sick - try taking loperamide with or after a meal or snack. It may also help if you stick to simple meals and you don't eat rich or spicy food.
  • headaches - make sure you rest and drink plenty of fluids. Don't drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if a headache lasts longer than a week or is severe.
  • wind - steer clear of foods that cause wind like lentils, beans and onions. It might also help to eat smaller and more frequent meals, eat and drink slowly, and exercise regularly. There are products you can buy from a pharmacy to help with wind, such as charcoal tablets or simethicone. One product is available which contains both loperamide and simethicone.

7. Pregnancy and breastfeeding

It's not known if loperamide is safe to take in pregnancy.

If you're trying to get pregnant or you're already 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.

Loperamide and breastfeeding

It's generally safe to take loperamide for a couple of days while you're breastfeeding. Very small amounts of loperamide may get into breast milk but not enough to harm your baby.

If you want to take loperamide for more than 2 days, talk to your doctor.

If your baby was premature, has a low birth weight or has other health problems, talk to your doctor before taking loperamide.

Important

Tell your doctor if you're trying to get pregnant, are already pregnant or if you're breastfeeding.

8. Cautions with other medicines

There are some medicines that may interfere with the way loperamide works.

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

  • ritonavir - a medicine used to treat HIV infection
  • quinidine - a medicine used to treat abnormal heartbeats or malaria
  • itraconazole or ketoconazole - medicines used to treat fungal infections
  • gemfibrozil - a medicine used to treat high cholesterol
  • desmopressin - a medicine for bedwetting or peeing too much
  • other medicines for diarrhoea, constipation, or for other stomach and bowel problems

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.

Important

Tell your doctor or pharmacist if you're taking any other medicines, including herbal medicines, vitamins or supplements.

9. Common questions

Page last reviewed: 09/02/2018
Next review due: 09/02/2021