Loperamide (Imodium): Uses, How to Take, Dosage & Side Effects

Loperamide is a medication used to treat acute or chronic diarrhea that’s not caused by an infection. It works by slowing down bowel movements, which allows stool to stay in the intestines longer. This gives the body more time to absorb water, resulting in firmer stools and fewer trips to the bathroom.

You can find loperamide in most US pharmacies under the brand name Imodium, which is available in 2 mg tablets or liquid form. Generic versions labeled loperamide hydrochloride are also widely available. This medication should only be used under a doctor’s guidance, after determining the cause of diarrhea. It is not suitable for young children, pregnant or breastfeeding women, or anyone with an intestinal infection.

Loperamide should never be used to treat diarrhea caused by bacterial infections or antibiotic-related conditions, as this can worsen the illness. Always talk to a healthcare provider before using it, especially if symptoms include fever, bloody stools, or abdominal pain.

Indications for use

Loperamide (Imodium) is prescribed to relieve:

• Sudden, non-infectious diarrhea

• Chronic diarrhea related to inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis

• Excessive fluid or electrolyte loss in people with ileostomies or colostomies

It works by binding to opioid receptors in the intestines, which reduces contractions and slows intestinal movement. This allows more water and nutrients to be absorbed, making stools firmer. Loperamide also strengthens the anal sphincter, helping decrease urgency and accidental leakage.

Most people notice improvement within about 48 hours after starting treatment.

Dosage and how to take it

Loperamide should be taken by mouth with a glass of water, at the times prescribed by a doctor.

For adults

• Acute diarrhea: The usual starting dose is 4 mg (two 2 mg tablets), followed by one 2 mg tablet after each loose stool, up to a maximum of 16 mg (eight 2 mg tablets) in 24 hours.

• Chronic diarrhea: The initial dose is also 4 mg (two 2 mg tablets). The doctor may adjust the dose to maintain one or two solid bowel movements per day, usually between one and six 2 mg tablets daily. Do not exceed eight 2 mg tablets per day.

For children

For children over 6 years old, the dose should be determined by a pediatrician based on the child’s age and weight.

Stop taking loperamide once stools become solid, if you haven’t had a bowel movement for 24 hours, or as advised by your doctor. If symptoms don’t improve after two days, or if you notice bloating or abdominal swelling, stop using it and consult your healthcare provider.

During treatment, drink plenty of fluids to prevent dehydration. Stick to foods that are gentle on the digestive system, such as white bread, rice, pasta, lean meats, and peeled fruits. 

Possible side effects

Common side effects of loperamide include constipation, dizziness, drowsiness, nausea, dry mouth, stomach pain, headache, and excess gas.

Stop using the medication and contact a doctor if you develop watery or bloody stools, worsening diarrhea, stomach pain or bloating, rapid or irregular heartbeat, chest fluttering, shortness of breath, or sudden dizziness.

Seek emergency care immediately if you experience signs of a severe allergic reaction such as difficulty breathing, throat tightness, swelling of the mouth, tongue, or face, hives, blistering or peeling skin, fever, sore throat, or burning eyes.

Who should not take loperamide

Loperamide (Imodium) should not be used by:

• Children under 6 years old

• Children over 6 years old with acute or persistent diarrhea

• People with diarrhea that includes blood or high fever

• People with ulcerative colitis, bacterial enterocolitis, pseudomembranous colitis caused by antibiotics, or abdominal pain without diarrhea

It should also be avoided during pregnancy and breastfeeding unless prescribed by a healthcare provider. People who are allergic to loperamide or any of the ingredients in the tablet should not use it.