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Treatment Name: Loperamide (Imodium®)

Loperamide (Imodium®) is a Supportive Care Therapy to treat Diarrhea

How does loperamide (Imodium®) work?
Loperamide (Imodium®) is designed to slow down the movement of the intestines and increase the time it takes for food and liquids to move through the digestive tract. This gives the intestines more time to absorb liquids, which helps to make stools more solid.

Loperamide may also decrease incontinence (having an unintentional bowel movement) and urgency to have a bowel movement.

Goals of therapy:
Loperamide (Imodium®) is taken to resolve or decrease episodes of diarrhea (watery bowel movements) and is commonly taken on an as needed basis with the goal of treating diarrhea. Loperamide may also help to decrease bloating, cramping, or stomach pain associated with diarrhea, as well as pain around the rectum resulting from frequent loose stools.

In certain cases, loperamide may be taken with medicines known to cause diarrhea in order to prevent diarrhea before it occurs. If you do not have diarrhea, you should not take loperamide to prevent loose stools without first speaking with your doctor or pharmacist.

Loperamide (Imodium®) is available as an over-the-counter medication (OTC) and can be purchased without a prescription. Loperamide may also be prescribed by a doctor and dispensed by a pharmacist.


Create your own Treatment Tracker

Loperamide (Imodium®) for diarrhea:

  • First dose: Loperamide (Imodium) 4 mg (two 2 mg capsules or tablets) by mouth once,
    • then 2 mg by mouth every 4 hours as needed for each loose stool
    • Maximum daily dose is 16 mg (eight capsules or tablets) per day

Loperamide is usually taken at home and improvement in symptoms should occur within 24 - 48 hours. If improvement is not seen, contact your doctor or go to the nearest emergency department.

Keep a journal and track the days and times when your bowel movements are:

  • Watery
  • Loose
  • Soft
  • Formed
  • Hard

A journal documenting bowel movement frequency and consistency will help you know whether loperamide is working and help you and your doctor manage the diarrhea.

High-dose loperamide (Imodium®) or diarrhea specifically caused by Irinotecan treatment:

  • First dose: Loperamide (Imodium) 4 mg (two 2 mg capsules or tablets) by mouth once
    • then 2 mg by mouth every 2 hours scheduled while awake,
    • then 4 mg (two 2 mg capsules or tablets) by mouth every 4 hours scheduled while sleeping. Set your alarm clock to wake you up every 4 hours so you can take your dose
    • Taking loperamide this way will result in a total daily dose of roughly 24 mg
  • After treatment with irinotecan, loperamide should be taken as directed until you have not had a bowel movement for 12 hours, then you may stop taking loperamide until the next cycle of chemotherapy. Call your doctor if diarrhea returns

Side Effects

In the prescribing label information (loperamide or Imodium® package insert), the most commonly reported side effects from loperamide (Imodium®) are shown here. The exact percentages of patients that will experience loperamide side effects is unknown because it has been used under widely varying patient populations in a variety of clinical trials:

  • Constipation (2 - 5%)
  • Dizziness (1%)
  • Nausea (1%)
  • Abdominal cramping (1%)
  • Abnormal heart rhythm (rare, exact % unknown)
  • Rash (rare, exact % unknown)
  • Trouble urinating (exact % unknown)
  • Drowsiness (exact % unknown)

Loperamide should be used in pregnant women only if the potential benefits to the mother outweigh the potential risks to the unborn baby as determined by your doctor.

When using loperamide in doses listed above, it is extremely unlikely that heart problems will occur due to loperamide. When loperamide is recommended by your doctor or pharmacist, the risk of not taking loperamide and resulting diarrhea-associated problems is likely much greater than the risk of side effects from loperamide.

Side effect videos Side Effect Videos
DiarrheaDiarrheaConstipationConstipationNausea and VomitingNausea and Vomiting


How often is monitoring needed?
Labs (blood tests) may be checked if you are experiencing significant diarrhea. Labs often include: Comprehensive Metabolic Panel (CMP), magnesium, plus any others your doctor may order.

If diarrhea lasts for more than 2 days or gets worse while taking loperamide (Imodium®), or you have abdominal swelling, call your doctor as these may be signs of a more serious condition.

Diarrhea can quickly cause dehydration and electrolyte problems, especially when severe. It is important to stay hydrated to keep up with fluid that is lost through bowel movements.

How often is imaging needed?
Imaging may be checked if there is any concern of any serious abdominal problems. Imaging may include: X-rays or computerized tomography (CT) scans.

How might blood test results/imaging affect treatment?
Depending upon the results, your doctor may advise to continue loperamide as planned, add additional medicines to treat diarrhea, switch to an alternative therapy, or for severe cases, recommend hospitalization to manage diarrhea, dehydration, and electrolytes.

Questions to Ask Your...

A better understanding of your treatments will allow you to ask more questions of your healthcare team. We then hope that with the answers, you will get better results and have greater satisfaction with your care. Because we know it's not always easy to know what questions to ask, we've tried to make it easy for you!

Choose any healthcare provider below to see common questions that you may want to ask of this person. Then, either print each list to bring to your clinic visits, or copy the questions and send them as a message to your healthcare team through your electronic medical record.

ChemoExperts Tips

  • Do not take loperamide if you have an active intestinal infection with a certain type of bacteria known as Clostridium difficile, or “C. diff”
  • If you notice blood in your stool, are experiencing severe stomach cramps, feel dizzy, have chills or a fever (100.4°F), contact your doctor immediately or go to the nearest emergency department
  • If you notice stomach cramping with diarrhea, especially after eating dairy products such as milk, cheese, or yogurt, or when taking antibiotics, consider changing your diet to the “B.R.A.T. diet = B = Bananas, R = Rice, A = applesauce, T = Toast” until your symptoms from diarrhea resolve
  • Taking more than the maximum daily dose of loperamide can increase your risk of developing an abnormal heart rhythm. However, heart problems from loperamide are extremely rare and been reported in patients taking loperamide in high doses for extended periods of time, often without a doctor’s supervision
  • Loperamide should not be given to children less than 12 years of age, unless prescribed by a doctor
  • If you are taking antibiotics, ask your doctor or pharmacist before you start taking loperamide
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Loperamide (Imodium®), we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Loperamide (Imodium®). Depending upon your income, they may be able to help cover the cost of:

  • Loperamide (Imodium®)

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Loperamide (Imodium®) and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

Share this page:


1) Loperamide (Imodium) package insert (drug label Information).

 2) Abigerges D, Armand JP, Chabot GG, et al. Irinotecan (CPT-11) high-dose escalation using intensive high-dose loperamide to control diarrhea. J Natl Cancer Inst 1994;86(6):446-449.

3) de Lemos ML, Guenter J, Kletas V. Loperamide and cardiac events: Is high-dose use still safe for chemotherapy-induced diarrhea? J Oncol Pharm Pract. 2017.

Created: July 22, 2017 Updated: November 6, 2018

What is Diarrhea?

Many diarrhea treatment options exist. Watch our diarrhea side effect effect video to learn more about diarrhea and available treatments, many of which are available over-the-counter.

What is a CMP?

A Comprehensive Metabolic Panel (CMP) is a frequently ordered blood test that tells clinicians the status of your: 1) Electrolytes & Acid/Base status2) Kidney function, 3) Liver function, 4) Blood sugar, and 5) Calcium at the time the test was taken. It is commonly used to monitor liver and kidney function when beginning new medications such as chemotherapy. A total of 14 tests are run simultaneously and are shown below.

Electrolytes & Acid/Base status:
1) Sodium, 2) Potassium, 3) Carbon dioxide, 4) Chloride

Kidney Function:
5) BUN (blood urea nitrogen), 6) Serum creatinine (Scr)

Liver Function:
7) AST, 8) ALT, 9) Total bilirubin, 10) Alk Phos, 11) Albumin, 12) Total protein

Blood sugar:
13) Serum glucose

14) Serum calcium