What it is used for
- Short-term relief of acute diarrhea
- Ongoing diarrhea managed by a clinician (for example with some bowel conditions)
- Reducing output from an ileostomy (under medical guidance)
How it works
Loperamide slows the movement of the gut so that more water is absorbed and stools become firmer and less frequent. It acts mainly in the bowel and is not meant to treat the underlying cause.
How it is taken
Comes as capsules, tablets, melt-in-mouth tablets, and oral liquid. It is taken by mouth, often after a loose stool. Take only as the label or your pharmacist directs, and never exceed the stated amount, as higher amounts can be dangerous.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Constipation
- Stomach cramps
- Bloating
- Dizziness
- Dry mouth
Serious effects — get help
- Severe constipation or signs of bowel blockage (swollen, painful abdomen, no wind or stool)
- Irregular or fast heartbeat, fainting (especially with high or excessive amounts)
- Severe allergic reaction
- Ongoing diarrhea with high fever or blood in the stool needs urgent care, not just loperamide
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Medicines that affect heart rhythm (QT interval)
- Certain drugs that raise loperamide levels (some antifungals, certain antivirals)
- Quinidine
Who should take care
- Do not use if you have blood in your stool or a high fever; see a clinician instead
- Not generally suitable for young children without medical advice
- Avoid in certain bowel conditions where slowing the gut is dangerous
- Never take more than directed; misuse of large amounts has caused serious heart problems
- Keep up fluids to avoid dehydration, and seek care if diarrhea lasts beyond a couple of days