Loperamide belongs to the family of medications called antidiarrheals. Loperamide, along with rehydration therapy (fluids and electrolytes), is used to treat short bouts of diarrhea that are not caused by a bacterial infection. It is also used to treat chronic diarrhea caused by inflammatory bowel disease (e.g., Crohn's disease) and to reduce the amount of stool produced for people who have ileostomies, colostomies, or have had part of their intestines removed.

It works by affecting the nerves in the intestines to reduce the amount of stool produced, reduce stool frequency, make stools more solid, and reduce cramping.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

For adults and children 12 years of age and older who have acute or chronic diarrhea, the recommended dose of loperamide is a starting dose of 4 mg, followed by a 2 mg dose after each loose bowel movement (or bout of diarrhea). Do not exceed 16 mg per day. For chronic diarrhea, once the optimal daily dose has been established, this dose can be given as a single daily dose or in divided doses.

Regular tablets should be taken with liquids. The quick-dissolve tablets can be taken without liquids. Loperamide tablets and capsules are not suitable for children under the age of 6 years old.

Children 6 to 12 years of age (10 kg to 20 kg) can use this medication for acute or chronic diarrhea if recommended by a doctor. For children 6 to 8 years old (or weighing 20 kg to 30 kg) the recommended dose for the first day is 2 mg twice daily. For children 8 to 12 years of age who weigh over 30 kg, the recommended dose for the first day is 2 mg 3 times daily. If the diarrhea continues, then the medication is given only after a loose bowel movement, and the amount to be given depends on the weight of the child. Contact your doctor or pharmacist for the recommended amount.

For children 2 to 5 years old the dose is based on body weight and will be calculated by your child's doctor.

For liquid forms of loperamide, use a syringe to measure each dose as this gives a more accurate measurement than household teaspoons.

Stop using loperamide if you have a solid or hard stool or if you go for 24 hours without a bowel movement. If you have acute (not chronic) diarrhea, see your doctor if it has not improved within 48 hours.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with the recommended dosing schedule (after each loose bowel movement). If it is almost time for your next dose, skip the missed dose and continue with the recommended dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not use this medication if you:

• are allergic to loperamide or any ingredients of the medication
• have acute dysentery (characterized by blood in the stool and fever)
• have acute ulcerative colitis
• have diarrhea caused by certain bacteria (e.g., salmonella, shigella and campylobacter)
• have pseudomembranous colitis (severe antibiotic-associated diarrhea)
• should avoid being constipated
• should not have the movement of the of intestines slowed (e.g., ileus, toxic megacolon)

Do not give this medication to children less than 2 years of age.

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• burning or prickly sensation on the tongue (quick-dissolve tablets)
• dizziness
• drowsiness
• dry mouth
• gas
• headache
• nausea or vomiting
• tiredness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• abdominal or stomach pain, cramps, discomfort, or distention
• constipation
• decreased coordination
• difficulty urinating
• rash
• shortness of breath

Stop taking the medication and seek immediate medical attention if any of the following occur:

• symptoms of a severe allergic reaction, e.g.:
• difficulty breathing
• hives
• peeling or blistering skin
• swelling of the mouth or throat

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Acquired immune deficiency syndrome (AIDS): People with AIDS should stop taking loperamide and contact their doctor if they experience abdominal swelling or distention.

Constipation: If you develop constipation, stop taking this medication and contact your doctor.

Drowsiness or dizziness: Loperamide may cause drowsiness or dizziness. Do not drive or operate machinery until you know how loperamide affects you.

Fluids and electrolytes: The loss of fluids and electrolytes (e.g., chloride, sodium) can occur if you have diarrhea. Loperamide helps with the symptoms of diarrhea but will not correct any fluid or electrolyte problems caused by diarrhea. Talk to your doctor or pharmacist about whether you need fluid and electrolyte replacement, also referred to as oral rehydration therapy.

Improvement in diarrhea: If your diarrhea has not improved after 48 hours of treatment with loperamide, stop taking it and contact your doctor.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Medical conditions: Loperamide should not be used by people with intestinal infections such as dysentery, which is often associated with severe diarrhea, fever, and blood in the stool, and other infections of the gut. A more serious problem of the bowel may develop if loperamide is used by some people with acute ulcerative colitis or a serious form of diarrhea associated with antibiotic use.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking loperamide, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: This medication is not recommended for use in children under the age of 12 except on the advice of a physician. Loperamide should not be given to children under 6 years of age without medical prescription and supervision. Loperamide tablets are not suitable for children under 6 years of age. Loperamide should not be used for children under 2 years of age. (See "Who should not take this medication.")

There may be an interaction between loperamide and any of the following:

• amiodarone
• "azole" antifungals (e.g., fluconazole, itraconazole, voriconazole)
• chlorpromazine
• desmopressin
• disopyramide
• dronedarone
• gemfibrozil
• haloperidol
• methadone
• procainamide
• quinine
• selpercatinib
• sotalol
• ziprasidone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.