Imodium

Pronunciation: loh-PER-a-mide.

Generic name
loperamide
Drug class
Antidiarrhoeal (opioid-receptor agonist acting locally in the gut)
Form
Capsule, tablet, or oral solution, 2 mg
Route
Oral
Legal status
Available over-the-counter in most markets; higher-strength prescription formulations also exist in some countries

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Imodium (5) · Full directory

What loperamide is and how it works

Imodium is an over-the-counter (and, at higher prescription strengths in some countries, prescription-only) medicine used to reduce the frequency of diarrhoea. (1)

Take Imodium exactly as directed on the label or by your prescriber. Never take more than the maximum daily dose -- doing so, including through misuse, has caused serious and sometimes fatal heart rhythm problems.

Mechanism of action: how loperamide works

Loperamide is a peripherally acting opioid-receptor agonist that binds to opioid receptors in the gut wall, slowing intestinal motility and increasing transit time, which reduces stool frequency and increases stool consistency. At recommended doses it does not cross the blood-brain barrier appreciably, which is why it lacks the central effects of other opioids at normal doses; at supratherapeutic doses this barrier can be overwhelmed, contributing to its misuse-related cardiac toxicity. (1)

What loperamide is used for

Acute diarrhoea

Used to reduce the frequency of sudden-onset diarrhoea in adults and children (age restrictions vary by country and product, typically age 2 or 12 and older). (1)

Chronic diarrhoea and IBS-related diarrhoea

Used under medical guidance for chronic diarrhoea linked to inflammatory bowel disease in adults, and for diarrhoea associated with irritable bowel syndrome after a doctor's diagnosis. (1) (2)

Before taking loperamide

Do not take / not appropriate for

  • Do not take Imodium if you have blood in your stool or a high fever with diarrhoea -- see a doctor instead, since this can indicate a serious infection needing different treatment. (all countries) (1)
  • Do not take Imodium if you have abdominal pain without diarrhoea, or if you have been diagnosed with acute ulcerative colitis or certain bacterial gut infections, without your prescriber's specific advice. (all countries) (1)
  • Do not give to children under 2 years of age (or under 12 for some products) unless a doctor directs it. (varies by product and country) (1) (6)

Tell your clinician about

  • Any heart rhythm problems or family history of them.
  • Any liver problems.
  • All other medicines you take, since some can raise loperamide levels in your body.
  • Pregnancy or breastfeeding.
(1)

How to take loperamide

  • Take by mouth, following the exact dose on the product label or from your prescriber.
  • Never take more than the maximum daily dose stated on the label or by your prescriber -- taking too much has caused serious, sometimes fatal heart problems.
  • Drink plenty of fluids while you have diarrhoea to help prevent dehydration.
  • If symptoms do not improve within 48 hours (acute diarrhoea), seek medical advice promptly, and let the clinician you see advise on whether to continue or stop Imodium.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Imodium is usually taken as needed after loose stools rather than on a fixed schedule, so a missed dose does not usually apply. do not take an extra dose doses -- stay within the maximum daily amount.

Overdose

Seek emergency medical help immediately if you or someone else has taken more than the recommended dose, especially if there are signs of an irregular heartbeat, fainting, or severe drowsiness -- overdose has caused fatal heart rhythm problems. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Constipation.

What to notice: Constipation.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea.

What to notice: Nausea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Abdominal cramping.

What to notice: Abdominal cramping.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Dizziness.

What to notice: Dizziness.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of a serious heart rhythm problem — boxed_warning

Symptoms: Fainting, a fast or irregular heartbeat, or severe dizziness, especially if more than the recommended dose has been taken.

Action: Seek emergency medical help immediately. This risk is strongly linked to taking more than the labelled or prescribed dose. (1)

Bloody diarrhoea, high fever, or severe abdominal pain — high caution

Symptoms: Blood or mucus in the stool, high fever, or severe abdominal pain.

Action: Do not treat this with Imodium -- see a doctor promptly, as it can indicate a serious gut infection needing different treatment. (1)

Signs of severe constipation or abdominal swelling — high caution

Symptoms: Severe bloating, no bowel movements, or worsening abdominal pain while taking Imodium.

Action: Stop and contact your doctor -- this can rarely indicate a serious bowel blockage (paralytic ileus). (1)

Interactions

  • Certain other medicines that strongly affect specific liver enzymes or a transport protein in the body (including some antifungal, antibiotic, and HIV medicines) can raise loperamide levels and increase the risk of heart problems -- tell your prescriber or pharmacist about all medicines you take. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Use only if your prescriber judges the benefits outweigh potential risks to the pregnancy -- discuss with your prescriber before use. (1) (2) (3) (4) (5) (6)

Breastfeeding

Small amounts pass into breast milk; not generally recommended while breastfeeding without your prescriber's advice. (1) (2) (3) (4) (5) (6)

Children

Not for children under 2 years old (or under 12 for some specific products) unless a doctor directs it; pediatric dosing is age- and weight-based and lower than the adult dose. (1) (2) (3) (4) (5) (6)

Elderly

No specific dose adjustment based on age alone is described in the source reviewed, but older adults may be more sensitive to constipation and dizziness side effects. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

Use with caution -- liver problems can affect how the body processes loperamide, increasing the risk of side effects. (1) (2) (3) (4) (5) (6)

Renal_impairment

Not specifically addressed with a dose adjustment in the source reviewed. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Confirmation that diarrhoea is not caused by a condition where loperamide should be avoided (e.g. bloody diarrhoea, certain colitis)

During treatment

  • Watching for improvement within about 48 hours for acute diarrhoea.
  • Watching for any signs of an irregular heartbeat or fainting, especially if more than the recommended dose is taken.
(1)

Storage

Store at room temperature, away from moisture and heat, out of reach of children.

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing.

United States

Indication: Acute nonspecific diarrhoea; chronic diarrhoea in IBD (adults)

Dose summary: OTC maximum 8 mg/day; prescription-strength maximum 16 mg/day. Adults/pediatric 13+: initial 4 mg, then 2 mg after each loose stool. Pediatric 2-12 years: 1-6 mg daily, age/weight-based.

Renal context: Not established in the source reviewed for this dossier. (1)

Mechanism of action

Hepatic guidance

Hepatic impairment can slow loperamide metabolism, potentially increasing systemic exposure and cardiac risk -- use with caution.

Overdose note

Overdose (including chronic misuse at doses far above the recommended maximum) has caused QT/QRS prolongation, Torsades de Pointes, Brugada-pattern ECG changes, syncope, cardiac arrest, and death; manage with cardiac monitoring and supportive care. (1)

Frequently asked questions

Is Imodium (loperamide) available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, it is approved and available over-the-counter in all of these regions, sometimes under different local brand names. (1) (2) (3) (4) (5) (6)

Can taking too much Imodium be dangerous?

Yes -- taking more than the recommended dose, including through misuse or abuse, has caused serious and sometimes fatal heart rhythm problems. Never exceed the labelled or prescribed maximum daily dose. (1)

When should I not take Imodium for diarrhoea?

Do not take loperamide if you have blood in your stool with fever (which can indicate bacterial dysentery), if your diarrhoea is caused by certain bacterial infections your clinician has identified, if you have active ulcerative colitis, or if you develop diarrhoea after taking an antibiotic (possible antibiotic-associated colitis). It should also not be used for stomach pain without diarrhoea, or in children under 2. (1)

What is the mechanism of action of loperamide?

Loperamide is a peripherally acting opioid-receptor agonist that binds to opioid receptors in the gut wall, slowing intestinal motility and increasing transit time, which reduces stool frequency and increases stool consistency. At recommended doses it does not cross the blood-brain barrier appreciably, which is why it lacks the central effects of other opioids at normal doses; at supratherapeutic doses this barrier can be overwhelmed, contributing to its misuse-related cardiac toxicity. (1)

What is the generic name of Imodium?

The generic name is loperamide. (1)

What class of drug is loperamide?

Imodium is classed as: Antidiarrhoeal (opioid-receptor agonist acting locally in the gut). (1)

References

  1. LOPERAMIDE HYDROCHLORIDE capsule -- full prescribing information (prescription-strength)U.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · accessed 2026-07-29 · source 1
  2. Imodium Original 2mg Capsules -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Johnson & Johnson / generic manufacturers · United Kingdom · accessed 2026-07-29 · source 2
  3. Loperamide -- list of nationally authorised medicinal products (PSUSA)European Medicines Agency (EMA) -- Pharmacovigilance Risk Assessment Committee (PRAC) periodic safety update assessment · European Union · accessed 2026-07-29 · source 3
  4. LOPERAMIDE-2 (Loperamide hydrochloride Tablets) Product MonographHealth Canada product monograph · Canada · accessed 2026-07-29 · source 4
  5. Over-the-counter (OTC) medicine monograph: Loperamide hydrochlorideTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 5
  6. Diamide (loperamide hydrochloride) New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-29 · source 6

Brand names by country

Single-ingredient loperamide names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • anti diarrheal2 mg, 1 mg/7.5mL · chain drug marketing association, inc.
  • Good Sense anti diarrheal2 mg · proficient rx lp
  • MEDIQUE Diamode2 mg · unifirst first aid corporation
  • dg health anti diarrheal2 mg, 1 mg/7.5mL · dolgencorp, llc
  • Good Sense antidiarrheal1 mg/7.5mL · preferred pharmaceuticals inc.
  • leader anti diarrheal1 mg/7.5mL, 2 mg · cardinal health 110, llc. dba leader
  • Imodium A-D2 mg, 1 mg/7.5mL · kenvue brands llc
  • CareOne Diarrhea Control1 mg/7.5mL, 2 mg · american sales company
  • WELMATE Anti Diarrheal Loperamide HCl2 mg · yyba corp
  • foster and thrive anti diarrheal1 mg/7.5mL, 2 mg · strategic sourcing services llc

United Kingdom

  • Imodium (2)MHRA licensed emc smpc confirmed · 2 mg · Johnson & Johnson Ltd

Canada

  • DIARRHEA RELIEF
  • IMODIUM LIQUI-GELS
  • DIARR-EZE - LIQ ORL
  • LOPERACAP
  • DIARR-EZE
  • IMODIUM CALMING
  • DOM-LOPERAMIDE HYDROCHLORIDE SOLUTION-ORL

Australia

  • Imodium (5)TGA OTC monograph confirmed · 2 mg · Johnson & Johnson Pacific Pty Ltd (and generics)

New Zealand

  • Imodium / Diamide / Nodia (6)Medsafe approved confirmed · 2 mg · Multiple (Johnson & Johnson and generics)
View brands in additional countries.

European Union

Imodium (3)

This page provides general reference information about Imodium (loperamide) and is not a substitute for advice from a pharmacist or prescriber. All dosing and treatment decisions should be made with your healthcare provider.

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