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Rifaximin

pronounced as(ri fax' i men)

Why is this medication prescribed?

Rifaximin 200-mg tablets are used to treat traveler's diarrhea caused by certain bacteria in adults and children at least 12 years of age. Rifaximin 550-mg tablets are used to prevent episodes of hepatic encephalopathy (changes in thinking, behavior, and personality caused by a build-up of toxins in the brain in people who have liver disease) in people at least 18 years of age who have liver disease. Rifaximin is in a class of medications called antibiotics. Rifaximin treats traveler's diarrhea by stopping the growth of the bacteria that cause diarrhea. Rifaximin treats hepatic encephalopathy by stopping the growth of bacteria that produce toxins and that may worsen liver disease. Rifaximin will not work to treat diarrhea that is bloody or occurs with fever.

How should this medicine be used?

Rifaximin comes as a tablet to take by mouth with or without food. When rifaximin is used to treat traveler's diarrhea, it is usually taken three times a day for 3 days. When rifaximin is used to prevent episodes of hepatic encephalopathy, it is usually taken twice a day. To help you remember to take rifaximin, take it around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take rifaximin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are taking rifaximin to treat traveler's diarrhea, your symptoms should improve within 24 to 48 hours after you start taking the medication. If your symptoms do not go away or they get worse, or if you develop a fever or bloody diarrhea, call your doctor.

Take rifaximin until you finish the prescription, even if you feel better. If you stop taking rifaximin to treat traveler's diarrhea too soon, your infection may not be completely cured and the bacteria may become resistant to antibiotics. If you stop taking rifaximin to prevent hepatic encephalopathy, you may experience symptoms of encephalopathy.

Other uses for this medicine

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This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What special precautions should I follow?

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Before taking rifaximin,

  • tell your doctor and pharmacist if you are allergic to rifaximin, rifabutin (Mycobutin), rifampin (Rifadin, Rifamate, Rifater, Rimactane), rifapentine (Priftin),any other medications, or any of the ingredients in rifaximin capsules. Ask your doctor or pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or have recently taken. Be sure to mention antibiotics. Your doctor may have to change the doses of your medications, monitor you carefully for side effects or treat your diarrhea differently.
  • tell your doctor if you have or have ever had severe liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking rifaximin, call your doctor.

What special dietary instructions should I follow?

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Unless your doctor tells you otherwise, continue your normal diet.

What should I do if I forget a dose?

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Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What side effects can this medication cause?

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Rifaximin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • nausea

  • stomach pain

  • dizziness

  • excessive tiredness

  • headache

  • muscle tightening

  • joint pain

Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:

  • watery or bloody diarrhea that may occur along with stomach cramps and fever during your treatment or for 2 months afterward

  • hives

  • rash

  • itching

  • difficulty breathing or swallowing

  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs

  • hoarseness

Rifaximin may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

What should I know about storage and disposal of this medication?

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Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.

In case of emergency/overdose

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In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.

What other information should I know?

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Keep all appointments with your doctor.

Do not let anyone else take your medication. Ask your pharmacist if you have any questions about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

Brand names

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  • Xifaxan®

Last Revised - 03/16/2011

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AHFS® Consumer Medication Information. © Copyright, 2014. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.