Generic name: loperamide [ loe-PER-a-mide ]
Brand names: Diamode, Imodium (various products), Maalox Anti-Diarrheal, Pepto Diarrhea Control, and others
Dosage forms: oral capsule, oral liquid, oral suspension, oral tablet, oral tablet, chewable
Drug class: Antidiarrheals

Medically reviewed by Carmen Pope, BPharm. Last updated on May 7, 2024.

What is loperamide?

Loperamide may be used to treat diarrhea or to reduce the amount of stool (poop) in people who have an ileostomy (which is when a surgeon re-routes your bowel through a small opening in your torso).

Loperamide works by acting on mu-opioid receptors in the gut to slow down the movement of the gut, which in turn, slows down contractions in the intestines. This allows more time for fluids and nutrients to be absorbed back into the body, which makes the stool less watery and decreases the number of times you go to the toilet.

Loperamide was FDA approved in 1976 and is available on prescription and over the counter.

Warnings

You should not use loperamide if you have ulcerative colitis, bloody or tarry stools, diarrhea with a high fever, or diarrhea caused by antibiotic medication.

Loperamide is safe when used as directed. TAKING TOO MUCH LOPERAMIDE CAN CAUSE SERIOUS HEART PROBLEMS OR DEATH.

Serious heart problems may also happen if you take loperamide with other medicines. Ask a doctor or pharmacist about safely using medications together.

Do not give loperamide to a child younger than 2 years old.

Children from the age 2 years to 5 years old should only used this medicine after consultation with a doctor.

Before taking this medicine

You should not use loperamide if you are allergic to it, or if you have:

• stomach pain without diarrhea;

• diarrhea with a high fever;

• ulcerative colitis;

• diarrhea that is caused by a bacterial infection; or

• stools that are bloody, black, or tarry.

Ask your doctor before using loperamide to treat diarrhea caused by taking an antibiotic (Clostridium difficile).

Do not give loperamide to a child younger than 2 years old. Children from the age 2 years to 5 years old should only use this medicine after consultation with a doctor.

Ask a doctor or pharmacist if it is safe for you to take loperamide if you have:

• a fever;

• mucus in your stools;

• liver disease; or

• a heart rhythm disorder.

Ask a doctor before using this medicine if you are pregnant.

You should not breast-feed while you are using loperamide.

How should I take loperamide?

Use loperamide exactly as directed on the label, or as prescribed by your doctor.

Loperamide is safe when used as directed. TAKING TOO MUCH LOPERAMIDE CAN CAUSE SERIOUS HEART PROBLEMS OR DEATH.

The usual adult dosage of loperamide for both acute and chronic diarrhea is 4 mg orally after the first loose stool, then 2 mg orally after each unformed stool. You should not take more than 16mg (8 capsules) per day.

Clinical improvement is usually seen within 48 hours.

The usual dosage of loperamide for a child varies depending on their age and weight. Always follow the directions on the label when giving loperamide to a child. A safe dose of loperamide is different for an adult than for a child.

Take loperamide with a full glass of water. Diarrhea can cause your body to lose fluids and electrolytes. Drink plenty of liquids to keep from getting dehydrated.

The loperamide chewable tablet must be chewed before swallowing.

Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Not all liquid forms of loperamide are the same strengths. Carefully follow all dosing instructions for the medicine you are using.

Store at room temperature away from moisture and heat. Do not allow the liquid medicine to freeze.

Stop taking loperamide and call your doctor if you still have diarrhea after 2 days of treatment, or if you also have stomach bloating.

What happens if I miss a dose?

Most people just take loperamide on an "as needed" basis and do not have a daily dosing schedule. If you miss a dose, you don't need to do anything.

If you are taking loperamide to reduce your frequency of bowel motions after an ileostomy, you may have a dosing schedule. Take the missed dose as soon as you remember but if it is almost time for the next dose, just skip that dose. Do not take two doses at once.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of loperamide can be fatal.

Overdose symptoms may include fast or irregular heartbeats, or fainting. A person caring for you should seek emergency medical attention if you pass out and are hard to wake up.

Never exceed the recommended dose for loperamide. The maximum dosage of loperamide in adults and children over the age of 13 years is 16mg (eight capsules) per day (24 hours).

What should I avoid while taking loperamide?

Avoid drinking tonic water. It can interact with loperamide and may cause serious heart problems.

Avoid becoming dehydrated by drinking plenty of fluids. Avoid vigorous exercise or exposure to hot weather if you are dehydrated.

Avoid driving or hazardous activity until you know how loperamide will affect you. Your reactions could be impaired.

Loperamide side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Stop taking loperamide and call your doctor at once if you have:

• diarrhea that is watery or bloody;

• stomach pain or bloating;

• ongoing or worsening diarrhea; or

• fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out).

Common side effects of loperamide may include:

• constipation;

• dizziness, drowsiness;

• nausea; or

• stomach cramps.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

What other drugs will affect loperamide?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take. Ask a doctor or pharmacist about safely using medications together.

Loperamide can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, heart problems, depression, mental illness, cancer, malaria, or HIV.

Many drugs can affect loperamide. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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