Rifaximin is used to treat travelers' diarrhea caused by Escherichia coli (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 (IBS) in adults whose main symptom is diarrhea.

Rifaximin is also used to lower the risk of a decline in 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.

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.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take rifaximin with or without food.

For travelers' diarrhea, rifaximin is usually taken for only 3 days. For IBS, rifaximin is usually taken for 2 weeks at a time. Follow your doctor's dosing instructions very carefully.

Use this medicine for the full prescribed length of time, even if your symptoms quickly improve. Skipping doses can increase your risk of infection that is resistant to medication. Rifaximin will not treat a viral infection such as the flu or a common cold.

Do not share this medicine with another person, even if they have the same symptoms you have.

Call your doctor if your symptoms do not improve after 24 to 48 hours, or if they get worse while using rifaximin.

Rifaximin does not treat all bacterial forms of travelers' diarrhea.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Traveler's Diarrhea:

200 mg orally 3 times a day for 3 days

Comments:
-This drug should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea caused by pathogens other than Escherichia coli.

Use: For the treatment of travelers' diarrhea due to noninvasive strains of E coli

Usual Adult Dose for Hepatic Encephalopathy:

550 mg orally twice a day

Comments:
-In trials, lactulose was used concomitantly in 91% of patients; differences in treatment effect of patients not using concomitant lactulose could not be assessed.

Use: For reduction in risk of overt hepatic encephalopathy recurrence

Usual Adult Dose for Irritable Bowel Syndrome:

550 mg orally 3 times a day for 14 days

Comments:
-If symptoms recur, patients can be retreated up to 2 times with the same dosage regimen.

Use: For the treatment of irritable bowel syndrome with diarrhea

Usual Pediatric Dose for Traveler's Diarrhea:

12 years or older: 200 mg orally 3 times a day for 3 days

Comments:
-This drug should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea caused by pathogens other than E coli.

Use: For the treatment of travelers' diarrhea due to noninvasive strains of E coli

You should not take rifaximin if you are allergic to rifaximin, rifabutin, rifampin, or rifapentine.

Tell your doctor if you have ever had:

• liver disease;

• diarrhea with a fever; or

• watery or bloody diarrhea.

Tell your doctor if you are pregnant or breastfeeding.

Rifaximin should not be given to a child younger than 12 years old.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

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).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

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

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 before using anti-diarrhea medicine.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Rifaximin may cause serious side effects. Call your doctor at once if you have:

• severe stomach pain, diarrhea that is watery or bloody (even if it occurs months after your last dose);

• fever; or

• fluid build-up around the stomach--rapid weight gain, stomach pain and bloating, trouble breathing while lying down.

Common side effects of rifaximin may include:

• swelling in your hands or feet;

• nausea;

• headache, dizziness;

• tiredness; 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.

Tell your doctor about all your other medicines, especially:

• cyclosporine;

• ketoconazole;

• warfarin (Coumadin, Jantoven);

• an antibiotic--clarithromycin, erythromycin;

• antiviral medicine--ritonavir, saquinavir; or

• heart or blood pressure medicine--amiodarone, quinidine, verapamil.

This list is not complete. Other drugs may affect rifaximin, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

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.