Generic Name: rifaximin (rif AX i min)
Brand Name: Xifaxan
What is rifaximin?
Rifaximin is an antibiotic that fights bacterial infection only in the intestines.
Rifaximin works differently from other antibiotics because it passes through your stomach and into your intestines without being absorbed into your blood stream. Because rifaximin treats only the intestinal tract, it will not treat infections of other parts of the body.
Rifaximin is used to treat travelers' diarrhea caused by E. coli in adults and children who are at least 12 years old. Most people get this infection by eating food or drinking fluids that have been contaminated with the E. coli bacteria.
Rifaximin is also used to treat irritable bowel syndrome in adults whose main symptom is diarrhea.
Rifaximin is also used to lower the risk of worsened brain function in adults with liver failure. Brain function can be affected when the liver stops working and cannot remove toxic substances from the body.
Rifaximin may also be used for purposes not listed in this medication guide.
What is the most important information I should know about rifaximin?
Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
What should I discuss with my healthcare provider before taking rifaximin?
You should not take this medicine if you are allergic to rifaximin, rifabutin, rifampin, or rifapentine.
To make sure rifaximin is safe for you, tell your doctor if you have:
diarrhea with a fever; or
watery or bloody diarrhea.
It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.
It is not known whether rifaximin passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.
Rifaximin should not be given to a child younger than 12 years old.
How should I take rifaximin?
Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
You may take rifaximin with or without food.
Use this medicine for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Skipping doses may also increase your risk of further infection that is resistant to antibiotics. Rifaximin will not treat a viral infection such as the flu or a common cold.
Call your doctor if your symptoms do not improve after 24 hours, or if they get worse while using rifaximin.
Rifaximin does not treat all bacterial forms of traveler's diarrhea.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking rifaximin?
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.
Rifaximin side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using rifaximin and call your doctor at once if you have:
severe stomach pain, diarrhea that is watery or bloody;
rapid weight gain, especially in your face and midsection.
Common side effects may include:
swelling in your hands, feet, or midsection;
tired feeling; or
abnormal liver function tests.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect rifaximin?
Tell your doctor about all your current medicines and any you start or stop using, especially:
lopinavir and ritonavir;
an antibiotic--azithromycin, clarithromycin, erythromycin;
antifungal medicine--itraconazole, ketoconazole; or
heart or blood pressure medicine--amiodarone, captopril, carvedilol, diltiazem, dronedarone, felodipine, quinidine, ranolazine, verapamil.
This list is not complete. Other drugs may interact with rifaximin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
See also: Side effects (in more detail)
More about Xifaxan (rifaximin)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- Pricing & Coupons
- En Español
- 47 Reviews – Add your own review/rating
- Drug class: miscellaneous antibiotics
Related treatment guides
Where can I get more information?
- Your pharmacist can provide more information about rifaximin.
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 4.02.
Date modified: September 05, 2017
Last reviewed: June 01, 2015