Rifaximin is an antibiotic that treats diarrhea caused by traveling or irritable bowel syndrome. It can also prevent a brain condition that can occur with severe liver disease. This medication comes in a tablet form that you can take by mouth with a glass of water. The brand name of this medication is Xifaxan®.

What is this medication?

RIFAXIMIN (ri FAX i men) treats diarrhea caused by bacteria. It may also be used to treat irritable bowel syndrome (IBS) with diarrhea. It can be used to prevent hepatic encephalopathy, a condition where the liver does not clear toxins from the body. It works by killing or preventing the growth of bacteria in your intestines that make toxins. It belongs to a group of medications called antibiotics. It will not treat colds, the flu, or infections caused by viruses.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Xifaxan

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Bloody or tarry stools
  • Fever
  • Liver disease
  • An unusual or allergic reaction to rifaximin, rifampin, rifabutin, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with water. Take it as directed on the prescription label at the same time every day. You can take it with or without food. If it upsets your stomach, take it with food. Take all of this medication unless your care team tells you to stop it early. Keep taking it even if you think you are better.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

This medication may interact with the following:

  • Cyclosporine
  • Estrogen or progestin hormones
  • Midazolam
  • Verapamil
  • Warfarin

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medication?

Tell your care team if your symptoms do not start to get better or if they get worse.

Do not treat diarrhea with over the counter products. Contact your care team if you have diarrhea that lasts more than 2 days or if it is severe and watery.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • Severe diarrhea, fever
  • Unusual vaginal discharge, itching, or odor

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Change in taste
  • Dizziness
  • Headache
  • Loss of appetite with weight loss
  • Nausea
  • Swelling of the ankles, hands, or feet

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store between 15 and 30 degrees C (59 and 86 degrees F). Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer needed or have expired:

  • Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
  • If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.