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Key takeaways
Lomotil and Imodium are two medications used to treat diarrhea. While they are both considered effective, they have some key differences to be mindful of.
Lomotil is a prescription drug and is classified as a Schedule V controlled substance. Imodium is sold over the counter.
The side effect profile of each drug is somewhat similar, but Lomotil can cause more central nervous system adverse events, such as drowsiness and confusion.
Lomotil (diphenoxylate/atropine) and Imodium (loperamide) are two antidiarrheal medications that are used to treat diarrhea. These medications work in similar ways to decrease the number and frequency of bowel movements. Lomotil and Imodium are designed to be taken for short-term diarrhea, which usually resolves within a few days after taking the medication.
Although an unpleasant experience, diarrhea is often mild and goes away on its own. The primary treatment for diarrhea is replacing fluids and electrolytes to prevent dehydration. However, medications like Lomotil and Imodium can be useful for acute diarrhea. Healthcare providers may also prescribe them for chronic diarrhea in certain situations.
Despite their similarities in uses, Lomotil and Imodium have some differences to be mindful of. For example, these drugs contain different ingredients and have certain limitations. We’ll explore their differences and similarities here.
What are the main differences between Lomotil and Imodium?
Lomotil
Lomotil is a brand-name drug that can only be obtained with a prescription. It contains a combination of diphenoxylate (an opioid) and atropine (an anticholinergic drug).
Diphenoxylate is the primary ingredient that binds to opioid receptors in the gut to slow intestinal motility. Atropine is added to discourage drug abuse since diphenoxylate is a controlled substance on its own.
Imodium
Imodium, also called Imodium A-D, is the brand name for loperamide. Unlike Lomotil, Imodium can be purchased over the counter (OTC). Therefore, it’s more widely available.
Loperamide’s chemical structure is similar to that of an opioid. It binds to opioid receptors in the intestinal wall to slow gut movement. It also blocks a chemical called acetylcholine and leads to decreased fluid and electrolyte loss. Because Imodium has minimal absorption in the central nervous system (CNS), it produces fewer CNS side effects than Lomotil, which has the opioid diphenoxylate as a primary ingredient.
| Main differences between Lomotil and Imodium | ||
|---|---|---|
| Lomotil | Imodium | |
| Drug class | Antidiarrheal | Antidiarrheal |
| Brand/generic status | Brand and generic versions available | Brand and generic versions available |
| What is the generic name? | Diphenoxylate/Atropine | Loperamide |
| What form(s) does the drug come in? | Oral tablet Liquid solution |
Oral tablet Oral capsule Liquid solution |
| What is the standard dosage? | Acute diarrhea:
2 tablets (2.5 mg diphenoxylate/0.025 mg atropine) four times daily until your diarrhea improves. Maximum daily dose: 20 mg of diphenoxylate Discontinue and consult a healthcare provider if symptoms do not improve within 10 days. Chronic diarrhea: As directed by a healthcare provider |
When used OTC for diarrhea:
4 mg after the first loose stool, and then 2 mg after each loose stool. Maximum daily dose: 8 mg Discontinue and consult a healthcare provider if your diarrhea doesn’t improve within 2 days. Healthcare providers may prescribe Imodium for chronic (ongoing) diarrhea in certain situations. The dosage for chronic diarrhea will be determined by your healthcare provider. |
| How long is the typical treatment? | Short-term diarrhea that resolves within 10 days. Long-term use may be needed for chronic diarrhea. | Short-term diarrhea that resolves within 10 days. Long-term use may be needed for chronic diarrhea. |
| Who typically uses the medication? | Adults and children 13 years of age and older | Imodium oral solution and tablets: Adults and children ages 6 years and older. Children ages 2–5 years only if recommended by a healthcare provider
Imodium capsules: Adults and children ages 12 years and older |
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Conditions treated by Lomotil and Imodium
Lomotil is FDA approved as an adjunctive treatment for diarrhea. This means that Lomotil is recommended as additional therapy along with other diarrheal treatments.
Like Lomotil, Imodium is FDA approved to treat several types of diarrhea. Imodium can be used to treat traveler’s diarrhea as well as diarrhea caused by medications such as those used for chemotherapy. Lomotil and Imodium can also treat chronic diarrhea caused by irritable bowel syndrome (IBS).
Diarrhea is typically defined as having loose stools three or more times in one day. Acute diarrhea is often mild and usually lasts no more than one or two days. Food poisoning is one of the most common causes of acute diarrhea.
Both drugs may also be used to treat chronic diarrhea, which is more severe and can last for more than four weeks at a time.
Is Lomotil or Imodium more effective?
Lomotil and Imodium are the most commonly used antidiarrheal agents. They are both effective and work relatively quickly to relieve symptoms of diarrhea. The best drug for you will depend on your overall condition and medical history, which should be assessed by your healthcare provider.
That being said, Imodium may be the more effective medication. Although there are no clinical trials that directly compare Lomotil and Imodium, some studies suggest that Imodium is a preferred option for treating diarrhea. One double-blind, crossover study found that loperamide was superior to diphenoxylate for treating chronic diarrhea, even at a 2.5-fold lower dose.
Another crossover study compared loperamide, diphenoxylate, and codeine for treating chronic diarrhea. The study found that loperamide and codeine were more effective than diphenoxylate for relief. Diphenoxylate was found to have the most side effects while loperamide was shown to have the least.
Coverage and cost comparison of Lomotil vs. Imodium
Most Medicare and insurance plans do not cover brand-name Lomotil. However, many insurance plans cover the generic version of the drug. Medicare Part D plans should cover diphenoxylate/atropine depending on your coverage. The average retail cost of generic Lomotil is around $130. Check with your pharmacy to see if you can use a discount savings card. SingleCare Lomotil coupons can lower the cost so that you pay around $10.
Imodium is an OTC drug that might not be covered by Medicare and insurance plans. Some plans may cover the generic form with a prescription. It’s best to check your insurance plan’s formulary to make sure. The average cost of loperamide is around $21. With a SingleCare discount, you can get generic loperamide tablets for about $9. In order to take advantage of OTC savings, you’ll still have to get a prescription from your healthcare provider.
Compare coverage and cost of Lomotil vs. Imodium |
||
|---|---|---|
| Lomotil | Imodium | |
| Typically covered by insurance? | No | No |
| Typically covered by Medicare? | No | No |
| Standard dosage | 2.5 mg diphenoxylate/0.025 mg atropine, quantity of 30 tablets | 2 mg, quantity of 24 tablets |
| SingleCare cost | $10 | $9 |
Common side effects of Lomotil vs. Imodium
According to its prescribing information, side effects of Lomotil include drowsiness, dizziness, and nausea. Compared to Imodium, Lomotil may have more CNS side effects including headache, restlessness, and confusion.
The most common side effect associated with Imodium is constipation. Other common side effects include dizziness, nausea, and abdominal cramps, according to StatPearls.
In higher doses, serious side effects of Lomotil could include severe drowsiness, hallucinations, lethargy, and slowed breathing (respiratory depression). Serious side effects of Imodium can include irregular heart rhythms, toxic megacolon, fainting, and severe skin reactions.
Drug interactions of Lomotil vs. Imodium
Lomotil can interact with drugs like monoamine oxidase inhibitors (MAOIs) and CNS depressants. Taking an MAOI, like selegiline or phenelzine, with Lomotil may increase the risk of hypertensive crisis, or dangerously high blood pressure. The risk of adverse effects may also be increased while taking CNS depressant drugs like barbiturates, benzodiazepines, and muscle relaxants.
Imodium has many potential drug interactions. Unlike Lomotil, Imodium is broken down in the liver mostly by the CYP3A4 enzyme. Drugs that inhibit, or block, this enzyme, such as ketoconazole, atazanavir, verapamil, and clarithromycin, can increase the levels of Imodium in the blood. As a result, taking any of those drugs with Imodium can increase the risk of adverse side effects. Imodium may also interact with drugs such as amiodarone, carvedilol, and quinidine, according to StatPearls.
Warnings of Lomotil and Imodium
Lomotil should not be used in children less than 6 years of age due to an increased risk of respiratory and CNS depression. Those with obstructive jaundice or known hypersensitivity to diphenoxylate or atropine should also avoid using Lomotil.
Imodium has been reported to cause serious heart problems, such as Torsade de Pointes and cardiac arrest, and death when taken in higher than recommended doses. It’s recommended to only take the minimum required dosage as instructed by your healthcare provider. Imodium should not be used in toddlers and infants less than 2 years of age due to the risk of respiratory and CNS depression.
Lomotil and Imodium should not be used to treat diarrhea caused by bacterial infections or by organisms, such as Clostridium difficile and Salmonella.
Consult your healthcare provider if you have any medical conditions before taking these medications. It’s recommended to take these medications with medical advice from your healthcare provider.
Frequently asked questions about Lomotil vs. Imodium
What is Lomotil?
Lomotil is a prescription medication used as adjunctive therapy for diarrhea. It is available in brand-name and generic versions. It can be taken for acute or chronic diarrhea in adults and children 13 years of age and older.
What is Imodium?
Imodium is an OTC drug that is FDA approved to treat diarrhea. It is typically used to treat Traveler’s diarrhea although it can also treat chronic diarrhea caused by IBS. Imodium can treat adults and children who are 2 years of age and older, however, children between 2 and 5 years of age should only take Imodium if recommended by a healthcare provider.
Are Lomotil and Imodium the same?
No. Lomotil and Imodium are not the same. Although they work in similar ways, Lomotil can only be obtained with a prescription and is a Schedule V controlled substance. Imodium can be purchased over the counter.
Is Lomotil or Imodium better?
Lomotil and Imodium are both effective drugs for treating diarrhea. Some research has shown that there is no significant difference in effectiveness between the two. However, other studies have shown that Imodium is more effective and better tolerated. Consult your healthcare provider for the best treatment option that’s right for you.
Can I use Lomotil or Imodium while pregnant?
Some healthcare providers may allow the use of Lomotil or Imodium during pregnancy only if it is necessary. Otherwise, Lomotil and Imodium are not generally recommended during pregnancy due to the possibility of fetal harm. Talk to your healthcare provider about antidiarrheal options while pregnant.
Can I use Lomotil or Imodium with alcohol?
It is not recommended to drink alcohol while using Lomotil or Imodium. Lomotil and Imodium may cause adverse effects such as drowsiness and dizziness. Drinking alcohol can increase these side effects.
Why is Lomotil banned?
Lomotil is not a banned drug. However, it is a Schedule V controlled substance as classified by the Drug Enforcement Administration. This means that there is a potential for misuse and abuse when using this drug. By itself, diphenoxylate, the main active ingredient of Lomotil, is a Schedule II substance with a higher potential for abuse.
Can you take Lomotil long-term?
Lomotil is not recommended to be used for more than 10 days for acute diarrhea. In some cases, Lomotil can be used for long-term use, especially for patients with chronic diarrhea. Long-term use of Lomotil should be monitored by a healthcare provider.
What happens if Imodium doesn’t stop diarrhea?
Imodium should relieve symptoms of mild diarrhea within 48 hours. If your diarrhea isn’t improving after two days, stop taking Imodium and contact a healthcare provider. If you experience any of the following, you should call your healthcare provider immediately:
- Blood in the stool
- Fever or temperature above 101.3°F
- Severe abdominal pain
- Passing six or more loose stools per day
- Diarrhea that lasts longer than 48 hours
- Symptoms such as severe lightheadedness, confusion, chest pain, or malaise
Sources
- FDA limits packaging for anti-diarrhea medicine loperamide (Imodium) to encourage safe use, Food and Drug Administration (2019)
- Lomotil prescribing information, DailyMed (2023)
- Imodium A-D prescribing information, DailyMed (2024)
- Traveler’s diarrhea, Centers for Disease Control and Prevention (2022)
- Chronic diarrhea, StatPearls (2023)
- A double-blind crossover comparison of loperamide with diphenoxylate in the symptomatic treatment of chronic diarrhea, Gastroenterology (1976)
- Double-blind cross-over study comparing loperamide, codeine, and diphenoxylate in the treatment of chronic diarrhea, Gastroenterology (1980)
- Loperamide, StatPearls (2024)
- Torsade de Pointes, StatPearls (2023)
- A comparison of lomotil and imodium in acute non-specific diarrhoea, Journal of International Medical Research (1977)
- A comparative study of loperamide and diphenoxylate in the treatment of chronic diarrhoea caused by intestinal resection, Annals of Clinical Research (1981)