Rifagut 550 Tablet: Uses, Dosage, Side Effects & FAQs

Written by: PlatinumRx Editorial Team Published on: 7 November 2026 Last reviewed on: 7 November 2026 Next review due: 7 November 2027

Rifagut 550 is a tablet that lowers the chance of another episode of hepatic encephalopathy, the confusion and drowsiness of serious liver disease. It is also used for a short course in adults with irritable bowel syndrome and diarrhoea. It is a prescription-only antibiotic in India, so no pharmacy can sell it without a valid prescription. The active ingredient, rifaximin 550 mg, works mostly inside the gut, where it reduces the bacteria that make ammonia.

Rifagut 550 is a single-ingredient antibiotic tablet for adults. Each tablet contains 550 mg of rifaximin, a rifamycin antibiotic. The 550 is the strength, so it is not the same as the 200 mg and 400 mg tablets.

The pack holds 10 tablets. The 200 mg and 400 mg tablets share this name, so check the number on your strip.

Rifaximin is an antibiotic that works almost only inside your gut. Think of it as a cleaner that never leaves the pipe it is cleaning. It stops the bacteria there from copying their own instructions, so fewer ammonia-making bacteria survive and less ammonia reaches the brain to cloud thinking.

Doctors usually prescribe Rifagut 550 for:

• Hepatic encephalopathy, where a damaged liver lets ammonia build up and thinking becomes muddled - in adults, to reduce the risk of another episode.
• Hepatic encephalopathy alongside lactulose - rifaximin is usually added to lactulose, and the pair may work better than lactulose alone.
• IBS-D, where irritable bowel syndrome causes loose, urgent stools - adults, for 14 days.
• Repeat IBS-D courses - if symptoms return, the course can be repeated up to twice more.

Rifagut 550 is not a general antibiotic, and it is not meant for travellers' diarrhoea at this strength.

Taken for the wrong problem, it wastes time and adds side effects without helping. Diarrhoea with fever or blood in it needs a doctor the same day, not this tablet.

1. Swallow the tablet whole with a glass of water.
2. Take it with or without food.
3. Keep to the same times each day, so the amount in your gut stays steady.
4. Ask your pharmacist before crushing or splitting it.
5. Finish the course your doctor set, even after you feel better.
6. If you also take lactulose, keep taking it exactly as prescribed.

Your doctor decides the dose and how long you take it. The schedules below come from the US prescribing information for rifaximin 550 mg tablets, where both uses are approved. The Indian Rifagut label was not available to compare.

In hepatic encephalopathy, the labelled dose is one 550 mg tablet twice a day, taken long term to keep episodes away. For IBS with diarrhoea, it is 550 mg three times a day for 14 days, repeated only if your doctor decides it is needed.

Never increase the dose on your own. A larger dose does not control confusion faster, and in severe liver disease more of the drug reaches your blood.

Rifagut 550 is for adults only and not approved under 18, so a child needs a paediatrician's advice. The 200 mg and 400 mg tablets are dosed differently, so never count tablets from another strength.

If someone takes too many tablets, call your doctor or go to the nearest hospital emergency department. Carry the strip or box with you.

Take the missed dose when you remember, unless the next one is almost due. In that case, skip it and carry on as usual. Never double up.

An IBS-D course runs 14 days, and your doctor judges how your stools and bloating changed. For hepatic encephalopathy it is a long-term medicine that lowers the chance of another episode, though it does not clear confusion that is already there; call your doctor if you feel no better or if confusion gets worse.

Keep the strip below 30°C, away from sunlight and damp, never in the bathroom. Keep it out of reach of children, and check the expiry date.

Most people take Rifagut 550 without much trouble. When side effects happen, they are usually mild.

Common and mild:

• Swelling in the feet and ankles
• Nausea
• Dizziness
• Tiredness
• Stomach pain or muscle cramps
• Itching

Rare but serious - stop the medicine and get help right away:

• Swelling of the face, lips or tongue, hives, or trouble breathing
• A spreading rash with blisters or peeling skin
• Severe or bloody diarrhoea that starts during or after the course
• Muscle pain, weakness or dark urine

In liver-disease studies, nausea, tiredness and stomach pain were about as common on a dummy tablet. Swelling and dizziness were more common with rifaximin, so tell your doctor.

Leg swelling, or a belly that keeps getting bigger, always needs a doctor's review. It can be fluid from the liver disease, not just the medicine.

• Anyone allergic to rifaximin or any other rifamycin antibiotic
• Anyone allergic to any other ingredient in the tablet
• Anyone with diarrhoea that has fever or blood in it — do not use this tablet to treat it
• Anyone whose diarrhoea is caused by an infection other than E. coli

Tell your doctor before taking Rifagut 550 if you have:

• Severe liver disease (more of the drug reaches your blood, so your doctor watches you closely)
• Kidney disease
• Pregnancy or trying to conceive (animal studies showed harm to the unborn baby, and there is no human data)
• Breastfeeding (it is not known whether it passes into breast milk)
• An age under 18 (it is not approved at this age, so a child needs a paediatrician's advice)
• An age above 65 (no dose change is usually needed)
• Warfarin or cyclosporine (the dose or monitoring may need to change)
• Regular alcohol use (alcohol can bring on liver-related confusion)

Always tell your doctor about every medicine, supplement or home remedy. If you have liver disease, ask about alcohol before your next drink.

Rifagut 550 lowers a risk; it does not replace urgent care. Get help quickly if you notice:

• New or worsening confusion, drowsiness, or difficulty speaking
• Vomiting blood, black stools, or a swollen, painful belly
• Diarrhoea with fever or blood, or diarrhoea that lasts more than 48 hours
• A rash with blisters, peeling skin, or swelling of the face or tongue
• Yellowing of the eyes or skin, or much less urine than usual
• Severe muscle pain with dark urine

Rifagut 550 is a gut antibiotic with two narrow jobs: lowering the chance of another episode of liver-related confusion, and short courses for IBS with diarrhoea. It works when you take it exactly as your doctor sets it, alongside lactulose if you have liver disease. Most side effects are mild and settle, but serious skin and allergic reactions need urgent attention. Never start it on your own or share your strip.