Kantrexil contains activated attapulgite 500 mg, an adsorbent clay. It is used for the symptomatic relief of acute diarrhoea — it thickens stools and binds toxins in the gut. It is not an antibiotic and does not treat the cause, so rehydration remains the priority.
What is Kantrexil?
Kantrexil contains activated attapulgite 500 mg. Attapulgite is a naturally occurring clay mineral — also called palygorskite — that has been activated by heating.
It works mechanically rather than chemically. Attapulgite passes through the gut without being absorbed into the body, and its large surface area adsorbs water, bacteria and toxins onto itself. The result is firmer stools and fewer irritants in contact with the bowel wall.
Because nothing is absorbed, it has a simple safety profile: the ingredient acts only inside the gut, and effects are largely limited to constipation and, through its binding action, interference with the absorption of other medicines taken at the same time.
The name causes confusion. Kantrexil resembles “kanamycin”, an antibiotic, and it is sometimes mistaken for one. It is not an antibiotic and has no antibacterial action. If you need an antibiotic for a gut infection, this is not it.
What is Kantrexil commonly used for?
Kantrexil is used for the symptomatic relief of acute diarrhoea:
- Acute non-specific diarrhoea, including travellers’ diarrhoea.
- Diarrhoea following dietary indiscretion or mild food-related upsets.
- Reducing stool frequency and looseness while the underlying cause settles on its own.
The word symptomatic is doing real work there. Most acute diarrhoea in an otherwise healthy adult is viral or self-limiting and resolves in a day or two regardless of treatment. Kantrexil makes those days more manageable; it does not shorten the illness or eliminate its cause.
Rehydration is the actual treatment. The danger in diarrhoea is fluid and electrolyte loss, not the frequency of stools. Oral rehydration solution — from any pharmacy — replaces both water and the salts lost, and it matters far more than anything that firms up a stool. This is especially true for children and older adults, where dehydration develops faster.
How Kantrexil fits into this medicine category
Within digestive medicines, Kantrexil is an adsorbent antidiarrhoeal:
| Group | Examples | How it works |
|---|---|---|
| Adsorbents | Attapulgite (Kantrexil), kaolin | Binds water and toxins in the gut |
| Motility-slowing | Loperamide | Slows bowel movement |
| Oral rehydration | ORS sachets | Replaces lost fluid and electrolytes |
| Antispasmodics | Hyoscine butylbromide (Hyospasmol) | Relieves cramping |
| Antiemetics | Metoclopramide (Adco-Contromet) | Reduces nausea and vomiting |
Adsorbents act only within the gut, which makes them a gentler option than motility-slowing medicines — particularly where there is any suspicion of an infective cause, since slowing the bowel can hold an infection in place. See the digestive, stomach and nausea medicines hub.
What to check before using Kantrexil
Separate it from other medicines by at least two to three hours. This is the most practically important point. Attapulgite binds things in the gut indiscriminately, including other medicines — antibiotics, and importantly the contraceptive pill, whose effectiveness can be reduced.
Speak to a pharmacist or doctor before use if:
- The diarrhoea is for a child, particularly under 3, or an older or frail adult. Rehydration is the priority and the threshold for review should be lower.
- There is blood or mucus in the stool, or a high fever. These suggest an infection needing assessment, not a symptomatic remedy.
- The diarrhoea has lasted more than two days, or keeps recurring.
- You have inflammatory bowel disease or another diagnosed bowel condition.
- You have recently taken antibiotics. Diarrhoea after a course can indicate a specific infection needing treatment.
- You have severe abdominal pain, or a suspected obstruction.
- You are pregnant or breastfeeding.
Buy oral rehydration solution at the same time, and use it.
Follow the pack instructions. This page does not set doses.
Possible cautions and when to ask a pharmacist or doctor
Constipation is the most likely effect, particularly if it is continued after the diarrhoea has settled. Stop taking it once stools are normal.
It reduces absorption of other medicines. If you take anything regularly — including the contraceptive pill, thyroid medicine, or an antibiotic — space it well away from Kantrexil, and ask a pharmacist about whether additional contraceptive precautions are needed.
It is a short-term remedy. Continuing it for more than a couple of days without advice risks masking a condition that needs diagnosis.
Fluids matter more than the tablets. Small, frequent sips of rehydration solution beat large amounts of water, which replaces fluid but not salts.
Seek medical attention for signs of dehydration — marked thirst, little or no urine, dizziness on standing, dry mouth, sunken eyes, or in a child unusual drowsiness or a dry nappy for many hours; for blood in the stool or black tarry stools; for a high fever; for severe or persistent abdominal pain; for persistent vomiting preventing fluid intake; or for diarrhoea lasting beyond a few days. Lower the threshold for infants, older adults, pregnant women, and anyone with diabetes or a suppressed immune system.
Related medicine guides
- Browse Digestive, Stomach & Nausea Medicines guides
- Read: Hyospasmol used for
- Read: Adco Contromet used for
Frequently asked questions
What is Kantrexil used for? Symptomatic relief of acute diarrhoea. It contains activated attapulgite, a clay that binds water and toxins in the gut.
Is Kantrexil an antibiotic? No. The name resembles an antibiotic’s, but it has no antibacterial action. It works mechanically inside the gut.
Does it treat the cause of diarrhoea? No. It relieves the symptom while the cause resolves. Rehydration is the treatment that matters.
Can I take it with my other medicines? Space them by at least two to three hours. Attapulgite binds other medicines and reduces their absorption, including the contraceptive pill.
Can I give it to my child? Ask a pharmacist first. In children the priority is oral rehydration solution, and dehydration develops faster than in adults.
How long can I take it? Short-term only, and stop when stools are normal. Diarrhoea lasting beyond two days needs assessment.