Indications
Rifaximin is an antibiotic that works mainly inside the gut. It is used for travellers’ diarrhoea caused by non-invasive E. coli bacteria (without fever or blood in the stool), to reduce the risk of repeated episodes of hepatic encephalopathy (confusion caused by liver disease) in adults, and for irritable bowel syndrome with diarrhoea (IBS-D). Doctors may also use it for bacterial overgrowth in the small intestine.
How It Works
Rifaximin belongs to the rifamycin group. It stops bacteria from making the proteins they need to grow. Very little is absorbed into the blood, so it acts on bacteria in the gut, including those that produce ammonia, a toxin that affects the brain in liver disease.
Dosage and Administration
- Travellers’ diarrhoea, adults and children 12 years and over: usually 200 mg three times a day for 3 days.
- Hepatic encephalopathy, adults: usually 550 mg twice a day, taken long term, as prescribed.
- IBS with diarrhoea, adults: usually 550 mg three times a day for 14 days, as prescribed.
- Other uses and children under 12: only as prescribed.
Take with or without food, with a glass of water. Finish the full course.
Interactions
Ciclosporin can raise rifaximin levels in the blood. Rifaximin may change the effect of Warfarin, so blood tests (INR) may need closer checking. It may make hormonal contraceptives less effective; ask your doctor whether extra protection is needed.
Contraindications
- Allergy to rifaximin or other rifamycins, such as Rifampicin.
- Bowel blockage.
- Travellers’ diarrhoea with fever or blood in the stool.
Side Effects
Wind, bloating, nausea, tummy pain, headache and dizziness. In people with liver disease, swelling of the legs and tiredness can occur. Urine may rarely turn reddish.
Get urgent medical help if you have:
- Severe or ongoing diarrhoea, especially watery or bloody, during or after treatment.
- Diarrhoea that gets worse or lasts more than 48 hours, or comes with high fever.
- Swelling of the face, lips or throat, a severe rash or difficulty breathing.
Pregnancy and Lactation
Avoid during pregnancy unless a doctor advises it. During breastfeeding, use only if a doctor advises it.
Precautions and Warnings
Do not use for diarrhoea with fever or blood in the stool; see a doctor instead. Tell your doctor if you have severe liver disease. People taking it for hepatic encephalopathy should not stop it without medical advice. Drink plenty of fluids during diarrhoea.
Overdose
Serious effects are unlikely because little is absorbed. Seek medical advice if a large amount has been taken.
Therapeutic Class
Antibiotic (rifamycin, acting in the gut).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.