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Generic Name

loperamide (loh PER a mide)


Trade Name

Imodium A-D


What is loperamide?

This drug acts to slow intestinal contractions. It also reduces the secretion of fluid by the bowel lining, thereby reducing the volume of stool and increasing its bulk.This drug acts to slow intestinal contractions. It also reduces the secretion of fluid by the bowel lining, thereby reducing the volume of stool and increasing its bulk.


What is it used for?

This drug can be used to treat almost any form of diarrhea, either acute or chronic. It may also be helpful in reducing the output from an ileostomy.


How do I take it?

Follow your physician’s instructions carefully. Loperamide may be taken on an empty stomach or with food or milk if stomach irritation occurs. The capsule may be opened and the contents sprinkled on food. Dehydration can be a concern when you have diarrhea for any extended period of time so it is important to drink plenty of fluids while taking loperamide. Store in a tightly closed container away from light. Keep all medications away from children. Never share your medications with anyone else.


What do I do for a missed dose?

If you are taking loperamide on a regular schedule for chronic diarrhea and miss a dose, take the dose as soon as you remember and then take the remaining doses for that day at evenly spaced intervals.


Are there interactions with food or beverages?

There are no known food interactions. Use alcohol with caution because loperamide may increase the intoxicating action of alcohol. Caffeine, which is found in coffee, tea, cola and chocolate, may aggravate diarrhea so its use should be avoided or reduced.


Are there interactions with other drugs?

An interaction generally means that one drug may increase or decrease the effect of another drug. Also, the more medications a person takes, the more likely there will be a drug interaction.

Interactions with this drug may occur with the following:

  • sedatives or tranquilizers
  • cholestyramine (Questran)


Is there a problem if I have another disorder or disease?

At times, a drug may have a different or enhanced effect when other diseases are present. At other times, the drug may worsen or effect another disease. When diarrhea is severe and especially when the patient is sick, it is as important to find the cause of the diarrhea as it is to control it. See your physician early and get the right tests done. If severe ulcerative colitis is present with sudden and severe diarrhea, do not use the drug unless you check with your physician.


What about allergies?

People who have known allergies or asthma may be at an increased risk for a reaction from any new medication. The physician should always know a patient’s allergy history. Signs of an allergic reaction are skin rash, hives and itching. Of course, a person should not take loperamide if there has been a previous reaction to this or a similar drug.


What if I’m pregnant, considering pregnancy or breast-feeding?

Most females now know that, if possible, no drug, including alcohol, should be taken during pregnancy or lactation. The potential danger, of course, is an injury to the baby. However, some drugs are much safer than others in this regard. So, the FDA has a grading system for each drug which reflects what is known medically. It ranks drugs from A, where medical studies show no evidence for danger to the fetus or mother, to B, C, D and X, where the medical evidence indicates that the risk to the fetus outweighs any benefit to the mother. Loperamide is ranked B. Always consult your physician before taking any drug during or when planning pregnancy.


What are the effects on sexual function?

There are no known adverse effects on sexual function.


Are there other precautions?

Loperamide may cause drowsiness or dizziness. Use caution when driving or operating hazardous equipment until the full effect of this drug has been determined. Consult your physician if fever or abdominal swelling develops or if diarrhea continues after 2 days.


How long is it safe to take loperamide?

Loperamide generally can be taken safely long-term. Forty-eight hours of regular use is usually needed to determine if loperamide will be effective in controlling acute diarrhea. If there is no improvement within several days, your physician should be contacted. Continued use for 10 days may be needed to evaluate its effectiveness in chronic conditions.


How about side effects?

Adverse reactions can occur with any drug, even over-the-counter medications. Some of these are mild such as a stomach upset, which may be avoided by taking the medication with food. Minor reactions may go away on their own but if they persist, contact the physician. For major reactions, the patient should contact the physician immediately.

For loperamide, the following are the observed side effects:


  • dizziness
  • drowsiness
  • dry mouth
  • constipation
  • rash


  • fever
  • abdominal swelling or pain
  • excessive gas
  • nausea
  • vomiting


A physician’s comment…

This drug has been around a long time. It is now available over-the-counter without a prescription so it is generally a safe drug. It is always important to know why diarrhea is present, so check with your physician. For mild, chronic diarrhea a high fiber diet may be helpful.