In the U.S.—

• Antidiarrheal
• Antibacterial

Rifaximin (rif-AX-i-min) is a medicine used to treat travelers' diarrhea caused by a bacteria called E. Coli.

This medicine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Tablets (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For rifaximin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to rifaximin, rifampin or rifabutin. Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Rifaximin has not been studied in pregnant women. However, studies in animals have shown that rifaximin may cause birth defects or other problems. Before taking this medicine, make sure your doctor knows if you are pregnant or if you become pregnant.

Breast-feeding—It is not known whether rifaximin passes into breast milk. However, rifaximin is not recommended during breast-feeding, because it may cause unwanted effects in nursing babies.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing the use of rifaximin in children under 12 years of age with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects of problems in older people. There is no specific information comparing use of rifaximin in the elderly with use in other age groups.

• Pseudomembranous colitis—Rifaximin may also cause this serious side effect.

Do not use rifaximin to treat your diarrhea if you have a fever or if there is blood in your stools. Contact your doctor.

Importance of diet and fluid intake while treating diarrhea:

• In addition to using medicine for diarrhea, it is very important that you replace the fluid lost by the body and follow a proper diet. For the first 24 hours, you should eat gelatin, and drink plenty of caffeine-free clear liquids, such as ginger ale, decaffeinated cola, decaffeinated tea, and broth. During the next 24 hours you may eat bland foods, such as cooked cereals, bread, crackers, and applesauce. Fruits, vegetables, fried or spicy foods, bran, candy, caffeine, and alcoholic beverages may make the condition worse.
• If too much fluid has been lost by the body due to the diarrhea, a serious condition (dehydration) may develop. Check with your doctor as soon as possible if any of the following signs or symptoms of too much fluid loss occur:
  • Decreased urination
  • Dizziness and lightheadedness
  • Dryness of mouth
  • Increased thirst
  • Wrinkled skin

Dosing—

The dose of rifaximin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of rifaximin. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets):
  • For diarrhea
    • Adults and children 12 years of age and older—200 milligrams taken three times a day for 3 days.
    • Children under 12 years of age—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

Check with your doctor if your diarrhea does not stop in 1 or 2 days or if you develop a fever or if you have blood in your stools.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

• Incidence not determined
  • Hives or welts;  itching skin;  large, hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs;  rash;  redness of skin 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome.

• More common
  • Headache 
  
  

• Less common
  • Difficulty having a bowel movement (stool);  vomiting 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.