Loperamide Hydrochloride
Loperamide is a medication used to treat sudden (acute) and long-lasting (chronic) diarrhea, including traveler's diarrhea. Loperamide Hydrochloride is used for Acute diarrhea, Chronic diarrhea and Diarrhea associated with inflammatory bowel disease.
Also called: Good Sense (United States) · Imodium Classic (United Kingdom) · Loperacap (Canada) · Gastrex (Australia) · Nodia (New Zealand)
Pronunciation: (loe-PER-a-mide).
Last medically reviewed: August 14, 2026, by Dr. Roshan Basnet, MBBS, MD (Internal Medicine).
- Generic name
- Loperamide hydrochloride
- Brand names
- Arret, Gastro-Stop, Diamode, Life Brand Loperamide, Diareze, Lomotil
- Drug class
- Digestive & Gastrointestinal
Availability and supply rules vary by country
Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand
Australia: Gastrex, A-WON DIARRHOEA RELIEF, Gastro-Stop, Pharmacy Action Diarrhoea Relief · Full directory
What Loperamide hydrochloride is and how it works
Loperamide is a medication used to treat sudden (acute) and long-lasting (chronic) diarrhea, including traveler's diarrhea. It works by slowing down the movement of the gut, which helps decrease the number of bowel movements and makes the stool less watery. Loperamide is not an antibiotic and does not treat the underlying cause of diarrhea, such as infection, but it can provide relief from symptoms. Key points for patients: Loperamide should not be used in children under 2 years of age. It is important to stay hydrated while using this medication. Do not use loperamide if you have bloody or tarry stools, high fever, or if your diarrhea is caused by certain infections. Always follow your healthcare provider's instructions and do not exceed the recommended dose.
Uses, formulations, monitoring, and supply rules can differ by patient, product, and country. Follow the exact local product information and professional advice.
Mechanism of action: how Loperamide hydrochloride works
Loperamide is a synthetic opioid agonist that acts on the mu-opioid receptors in the myenteric plexus of the large intestine. It inhibits peristalsis and prolongs transit time, reducing fecal volume and increasing stool viscosity. Loperamide does not cross the blood-brain barrier at therapeutic doses, minimizing central nervous system effects. (1)
What is Loperamide hydrochloride used for?
Acute diarrhea
Acute diarrhea
Chronic diarrhea
Chronic diarrhea
Diarrhea associated with inflammatory bowel disease
Diarrhea associated with inflammatory bowel disease
Reduction of volume of discharge from ileostomies
Reduction of volume of discharge from ileostomies
Before taking Loperamide hydrochloride
Do not take / not appropriate for
- hypersensitivity to loperamide, children under 2 years, acute dysentery (blood in stools, high fever), pseudomembranous colitis, and bacterial enterocolitis. (Contraindication)
- Not recommended in patients with abdominal distension or suspected ileus. (Contraindication)
Tell your clinician about
Loperamide hydrochloride dosage and how to take it
- General Instructions: Take loperamide exactly as directed by your healthcare provider. Do not exceed the recommended dose. Drink plenty of fluids to prevent dehydration.. Adult Dosing: For acute diarrhea: Start with 4 mg (usually 2 tablets) after the first loose stool, then 2 mg after each subsequent loose stool. Maximum: 16 mg per day. For chronic diarrhea: Dose may be adjusted by your doctor, usually starting at 4 mg per day, divided into two doses.. Pediatric Dosing: Children 6-12 years: Dosing is weight-based and should be determined by a healthcare provider. Not recommended for children under 2 years.. Administration: Take tablets or capsules by mouth with or without food. Oral solution should be measured carefully. Orally disintegrating tablets should be placed on the tongue to dissolve.. When To Seek Review: Contact your doctor promptly and let them advise on whether to continue or stop loperamide if diarrhea lasts more than 48 hours, if you develop abdominal swelling, or if you notice blood in your stool.. Storage: Store at room temperature, away from moisture and heat. Keep out of reach of children.
- This page does not provide a dose calculator. Dosing must follow the prescriber, pharmacist, or product label.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician.
Missed dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. do not take an extra dose to make up for a missed dose.
Overdose
Symptoms of overdose may include severe drowsiness, irregular heartbeat, fainting, or difficulty breathing. Seek emergency medical attention immediately. Cardiac monitoring and supportive care may be required.
Loperamide hydrochloride side effects
Side effects and their urgency vary; report severe, persistent, or concerning symptoms to a healthcare professional.
Constipation
Incidence: Reported in the clinician-authored database; frequency not established
Dizziness
Incidence: Reported in the clinician-authored database; frequency not established
Nausea
Incidence: Reported in the clinician-authored database; frequency not established
Abdominal pain
Incidence: Reported in the clinician-authored database; frequency not established
Dry mouth
Incidence: Reported in the clinician-authored database; frequency not established
Allergic reactions (rash, itching)
Incidence: Reported in the clinician-authored database; frequency not established
Severe constipation/ileus
Incidence: Reported in the clinician-authored database; frequency not established
Serious warnings
Do not use in children under 2 years — serious
Symptoms: Do not use in children under 2 years. Do not use if you have bloody or tarry stools or high fever. Serious heart problems can occur with high doses or misuse. Do not use for more than 2 days unless directed by a doctor. Use caution in patients with liver disease.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Contraindications recorded in the clinician database — serious
Symptoms: Contraindications recorded in the clinician database: Contraindications include hypersensitivity to loperamide, children under 2 years, acute dysentery (blood in stools, high fever), pseudomembranous colitis, and bacterial enterocolitis. Use with caution in hepatic impairment due to risk of accumulation and CNS toxicity. Not recommended in patients with abdominal distension or suspected ileus.
Action: Follow the urgency stated and seek prompt or emergency care when indicated.
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Recorded interactions | Loperamide may interact with medications that affect heart rhythm (such as quinidine, amiodarone), certain antifungals (ketoconazole, itraconazole), HIV medications (ritonavir), and other drugs that slow gut movement. Combining with other central nervous system depressants may increase drowsiness. Always inform your healthcare provider about all medications and supplements you are taking. | (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
The FDA-approved Imodium prescribing information reviewed for this page does not establish loperamide's safety in pregnancy with a specific numeric guidance; use during pregnancy is a decision for the prescriber managing the pregnancy, weighing the potential benefit against any potential risk.
Breastfeeding
The FDA-approved Imodium prescribing information reviewed for this page does not establish specific breastfeeding dosing guidance; discuss use of this medicine with your healthcare provider while breastfeeding.
Children
Frequency: Not applicable.. Weight Based: Not recommended for pediatric use.. Max Daily Dose: Not applicable.. Max Single Dose: Not applicable.. Age Restrictions: Safety not established in children under 2 years of age.
Renal Impairment
Renal impairment: the FDA-approved Imodium (loperamide) prescribing information states no dosage adjustment is required, because the drug's metabolites and unchanged drug are mainly excreted in the feces rather than the kidneys, and no pharmacokinetic data are available in renal impairment specifically. Hepatic impairment: the same label states loperamide should be used with caution in patients with liver disease, because reduced first-pass metabolism can raise drug exposure; patients with liver dysfunction should be monitored closely by their prescriber for signs of central nervous system toxicity (such as unusual drowsiness or confusion).
Hepatic Impairment
Renal impairment: the FDA-approved Imodium (loperamide) prescribing information states no dosage adjustment is required, because the drug's metabolites and unchanged drug are mainly excreted in the feces rather than the kidneys, and no pharmacokinetic data are available in renal impairment specifically. Hepatic impairment: the same label states loperamide should be used with caution in patients with liver disease, because reduced first-pass metabolism can raise drug exposure; patients with liver dysfunction should be monitored closely by their prescriber for signs of central nervous system toxicity (such as unusual drowsiness or confusion).
Monitoring
Storage
Follow the exact product label and keep medicines away from children.
Professional information
Clinician-facing context only. This section does not replace current product labeling.
General
Indication: Acute diarrhea
Dose summary: Initial dose of 4 mg, followed by 2 mg after each loose stool; adults and children 12 years and over should not exceed 4 caplets (8 mg of the 2 mg OTC strength product) in 24 hours for self-treatment without medical supervision.
Renal context: The FDA-approved Imodium (loperamide) prescribing information states no dosage adjustment is required in renal impairment, because the drug's metabolites and unchanged drug are mainly excreted in the feces rather than the kidneys (no specific pharmacokinetic data are available in renal impairment). For hepatic impairment, the label advises using loperamide with caution because of reduced first-pass metabolism, and recommends close monitoring for signs of CNS toxicity in patients with liver dysfunction. (1) (2)
Frequently asked questions
Can I use loperamide for all types of diarrhea?
No, loperamide is not suitable for diarrhea caused by certain infections (such as those with blood or high fever) or antibiotic-associated colitis. Always consult your doctor before use.
How quickly does loperamide work?
Loperamide usually starts to work within 1–3 hours after taking the first dose. Symptom relief may vary depending on the cause of diarrhea.
Is loperamide safe during pregnancy or breastfeeding?
Loperamide should only be used during pregnancy or breastfeeding if clearly needed and prescribed by a healthcare provider. Discuss risks and benefits with your doctor.
Can I drive or operate machinery while taking loperamide?
Loperamide may cause dizziness or drowsiness in some people. Avoid driving or operating heavy machinery until you know how it affects you.
What should I do if my diarrhea does not improve?
If diarrhea persists for more than 48 hours or worsens, seek medical advice promptly, and let the clinician you see advise on whether to continue or stop loperamide.
Can I take loperamide with other antidiarrheal medications?
Do not combine loperamide with other antidiarrheal drugs unless directed by your doctor, as this may increase the risk of side effects.
Is loperamide available over the counter?
Yes, loperamide is available over the counter in many countries, but higher strengths or larger pack sizes may require a prescription.
What happens if I take too much Loperamide?
Taking too much Loperamide can lead to serious heart problems, including abnormal heart rhythms, and other severe side effects such as central nervous system depression. Symptoms may include dizziness, fainting, and difficulty breathing. If an overdose is suspected, seek immediate emergency medical attention or call poison control.
Can I drink alcohol while taking Loperamide?
It is generally advisable to avoid or limit alcohol consumption while taking Loperamide. Alcohol can exacerbate dehydration, which is a common concern with diarrhea, and may also increase the risk of certain side effects like dizziness or drowsiness. Always consult your healthcare provider regarding alcohol use with any medication.
Is Loperamide safe during pregnancy?
Loperamide's safety during pregnancy is categorized as 'Consult doctor.' This means that its use should be carefully considered and discussed with a healthcare provider. They can assess the potential risks and benefits for both the mother and the fetus, and determine if Loperamide is the appropriate treatment option for your specific situation.
What is the mechanism of action of Loperamide hydrochloride?
Loperamide is a synthetic opioid agonist that acts on the mu-opioid receptors in the myenteric plexus of the large intestine. It inhibits peristalsis and prolongs transit time, reducing fecal volume and increasing stool viscosity. Loperamide does not cross the blood-brain barrier at therapeutic doses, minimizing central nervous system effects. (1)
What is the generic name of Loperamide Hydrochloride?
The generic name is Loperamide hydrochloride. It is sold under brand names including Arret, Gastro-Stop, Diamode, Life Brand Loperamide, Diareze, Lomotil.
What class of drug is Loperamide hydrochloride?
Loperamide Hydrochloride is classed as: Digestive & Gastrointestinal.
References
- MedGuideGlobal clinician-authored medicine record — loperamideMedGuideGlobal · International · accessed 2026-08-06 · source 1
- Imodium (loperamide hydrochloride) prescribing informationU.S. Food and Drug Administration · United States · accessed 2026-08-07 · source 2
- LOPERAMIDE HYDROCHLORIDE TABLET [YYBA CORP] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 3
- Loperamide — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 4
- anti diarrheal — FDA approval record (Drugs@FDA ANDA091292)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 5
- Loperamide — RxNorm normalized drug concept (RXCUI 6468)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 6
Brand names by country
Single-ingredient Loperamide hydrochloride 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 diarrhealtablet, tablet, film coated, capsule, liquid filled, solution · 2 mg, 1 mg/7.5mL · chain drug marketing association, inc.regulator source
- Good Sense anti diarrhealtablet, film coated · 2 mg · proficient rx lpregulator source
- MEDIQUE Diamodetablet · 2 mg · unifirst first aid corporationregulator source
- dg health anti diarrhealtablet, film coated, solution · 2 mg, 1 mg/7.5mL · dolgencorp, llcregulator source
- Good Sense antidiarrhealsolution · 1 mg/7.5mL · preferred pharmaceuticals inc.regulator source
- leader anti diarrhealsuspension, solution, tablet, film coated · 1 mg/7.5mL, 2 mg · cardinal health 110, llc. dba leaderregulator source
- Imodium A-Dcapsule, liquid filled, tablet, film coated, solution · 2 mg, 1 mg/7.5mL · kenvue brands llcregulator source
- CareOne Diarrhea Controlsuspension, tablet, film coated · 1 mg/7.5mL, 2 mg · american sales companyregulator source
- WELMATE Anti Diarrheal Loperamide HCltablet, capsule · 2 mg · yyba corpregulator source
- foster and thrive anti diarrhealsolution, tablet, film coated · 1 mg/7.5mL, 2 mg · strategic sourcing services llcregulator source
United Kingdom
- Imodium Classicreference source
- Norimodereference source
Canada
- DIARRHEA RELIEFregulator source
- IMODIUM LIQUI-GELSregulator source
- DIARR-EZE - LIQ ORLregulator source
- LOPERACAPregulator source
- DIARR-EZEregulator source
- IMODIUM CALMINGregulator source
- DOM-LOPERAMIDE HYDROCHLORIDE SOLUTION-ORLregulator source
Australia
- Gastrexreference source
- A-WON DIARRHOEA RELIEFreference source
- Gastro-Stopreference source
- Pharmacy Action Diarrhoea Reliefreference source
New Zealand
- Diamide Reliefreference source
- Nodiareference source
View brands in additional countries.
Philippines
Imodium