Imodium Side Effects: What They Are and How to Manage Them
Imodium (loperamide) is an over-the-counter (OTC) medication used to relieve diarrhea in adults and some children. Imodium can cause side effects that range from mild to serious. Examples include dizziness and drowsiness.
Imodium comes as an oral solution, oral capsule, and oral tablet called Imodium A-D. Unless otherwise noted, this article uses “Imodium” to describe all forms of the drug.
Keep reading to learn about common, mild, and serious side effects Imodium can cause. For a general overview of the drug, including details about its uses, see this article.
What are the more common side effects of Imodium?
Some people may experience mild to serious side effects during Imodium treatment. Examples of the drug’s commonly reported side effects include:
* To learn more about this side effect, see the “Side effects explained” section.
What are the mild side effects of Imodium?
Mild side effects have been reported with Imodium. These include:
- dizziness
- constipation*
- drowsiness*
In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist.
Imodium may cause mild side effects other than those listed above. See the drug’s label for details.
* To learn more about this side effect, see the “Side effects explained” section.
What are the serious side effects of Imodium?
Serious side effects have been reported with Imodium. These include:
- abdominal pain or swelling, which may indicate a possible blockage in your intestines
- heart rhythm problems*
If you develop serious side effects while taking Imodium, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.
* To learn more about this side effect, see the “Side effects explained” section.
Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Imodium, visit MedWatch.
Allergic reaction
For some people, Imodium can cause an allergic reaction. But it’s not clear how often this side effect occurs in people who take Imodium.
What might help
If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Imodium.
If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.
If your doctor confirms you’ve had a serious allergic reaction to Imodium, they may have you switch to a different treatment.
FAQ about Imodium’s side effects
Get answers to some frequently asked questions about Imodium’s side effects.
Are there any harmful effects from long-term use of Imodium or taking the drug every day?
Not necessarily, if you’re taking Imodium as directed on the drug label or by your doctor.
Imodium is not typically used long term. You’ll stop taking it once your diarrhea is relieved. If your diarrhea lasts for more than 2 days after starting Imodium, the manufacturer recommends contacting your doctor.
Your doctor can advise you on whether it’s safe to take Imodium for more than 2 days and tell you about any potential risks.
Is Imodium safe for elderly adults?
Yes, Imodium is generally safe for older adults (ages 65 years and older).
But keep in mind that older adults may have certain health conditions that increase their risk of side effects from Imodium. Examples include heart rhythm problems and liver disease.
To learn more about Imodium and possible age-related side effects, talk with your doctor or pharmacist.
Does Imodium affect blood pressure?
It’s not likely. Changes in blood pressure weren’t reported in the drug labels for Imodium oral solution, oral capsule, or oral tablet.
But diarrhea, which Imodium is used to treat, may lead to dehydration, and this can result in low blood pressure. For this reason, it’s important to stay hydrated by consuming plenty of fluids. You can also drink liquids with electrolytes, such as Pedialyte or Gatorade.
If you have other questions about how Imodium may affect your blood pressure, talk with your doctor or pharmacist.
Warnings for Imodium
Imodium can sometimes cause harmful effects in people with certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Imodium is a good treatment option for you. For example, if you have certain health conditions, taking Imodium could increase your risk of harm. These conditions may be referred to as contraindications.
Talk with your doctor about your health history before taking Imodium. Be sure to tell them if any of the following factors apply to you:
- fever
- black stool, bloody stool, or mucus in your stool
- liver disease
- heart rhythm problems
- previous allergic reaction to Imodium
- pregnancy
- breastfeeding
- alcohol consumption
Side effects explained
Learn more about some of the side effects Imodium may cause.
Constipation
Constipation is a possible side effect of Imodium. The drug labels for Imodium oral solution, oral capsule, and oral tablet do not report how common this side effect may be.
Constipation may cause symptoms such as:
- passing hard or dry stools
- pain or straining during bowel movements
- fewer than three bowel movements in 1 week
What might help
If you have constipation during Imodium treatment, stop taking it. This side effect usually goes away within a few days after stopping the medication.
If you have abdominal pain or swelling with constipation, contact your doctor right away. These could be symptoms of a blockage in your intestines. Your doctor can give you more information about what to do if this occurs.
Drowsiness
Drowsiness is a possible side effect of Imodium. The drug labels for Imodium oral solution, oral capsule, and oral tablet do not report how common this side effect may be.
Drowsiness could make certain activities dangerous, such as driving. Until you know how Imodium affects you, it may be best to avoid driving after taking it.
What might help
If you have bothersome drowsiness during Imodium treatment, talk with your doctor or pharmacist. They may suggest alternatives that are less likely to cause this side effect.
Heart rhythm problems
Heart rhythm problems are possible with Imodium. The drug labels for Imodium oral solution, oral capsule, and oral tablet do not report how common this side effect may be.
Heart rhythm problems may cause symptoms such as:
Taking a higher dose of Imodium than is recommended may increase the risk of this side effect.
What might help
If you have a heart rhythm problem, talk with your doctor before taking Imodium. They can recommend whether it’s safe to take the drug.
If you have symptoms of a heart rhythm problem during Imodium treatment, contact your doctor. But if your symptoms seem severe or life threatening, call 911 or your local emergency number. A healthcare professional can give you tests to check for a heart rhythm problem.
Keeping track of side effects
During your Imodium treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or using a combination of treatments.
Your side effect notes can include things such as:
- what dose of the drug you were taking when you had the side effect
- how soon you had the side effect after starting that dose
- what your symptoms were
- how your symptoms affected your daily activities
- what other medications you were taking
- any other information you feel is important
Sharing notes with your doctor will help them learn more about how Imodium affects you. They can then use this information to adjust your treatment plan if needed.
Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
What is Imodium and how does it work?
Imodium is a medication used to treat diarrhea. It works by slowing down the movement of the gut, which reduces the number of bowel movements and makes the stool less watery.
What are the common side effects of Imodium?
Common side effects of Imodium include dizziness, drowsiness, tiredness, headache, nausea, vomiting, dry mouth, and constipation.
Can Imodium cause serious side effects?
Yes, although rare, Imodium can cause serious side effects such as allergic reactions, severe constipation, stomach pain, and an irregular heartbeat. Seek medical attention if you experience these symptoms.
Who should avoid taking Imodium?
Individuals who are allergic to loperamide, those with a severe liver condition, or anyone with bloody or black stools should avoid taking Imodium. Always consult with a healthcare professional before use.
How can I manage mild side effects of Imodium?
To manage mild side effects like dizziness or drowsiness, avoid driving or operating heavy machinery. Stay hydrated and try eating light meals to help with nausea or dry mouth.
Can Imodium be taken with other medications?
Imodium can interact with other medications. It’s important to discuss your current medications with a healthcare provider to avoid adverse interactions.
How should I store Imodium?
Store Imodium at room temperature, away from excessive heat and moisture. Keep it out of reach of children and pets.
How long can I safely take Imodium?
Imodium is typically used for short-term relief. If your diarrhea persists for more than 48 hours, contact a healthcare professional for further advice.
