1 What is Xifaxan?

Brand: Xifaxan

Generic: Rifaximin

Xifaxan is a prescription-only antibiotic used to:

It is available in tablet form.

Have a question aboutXifaxan?Ask a doctor now

2 What to Know Before Using

Before using Xifaxan, you must know all about the risks and complications associated with it. Together with your doctor, you can decide whether the medication will do you more goods than the harms. 

Here are some factors to be considered before deciding to use this medicine:

Allergies: Inform your doctor about the allergies you have, such as to this medication, other medications, or to foods, dyes, or preservatives.

Pediatric: Safety and efficacy of rifaximin in children below 12 years have not been studied extensively. Consult your child’s doctor before using this medicine.

Geriatric: It may be used in elderly after assessing risks and benefits of the use.

Breastfeeding: It may be used in a nursing mother after assessing risks and benefits of the use.

Drug Interactions: Taking two medicines together can be harmful due to possible interactions. In other cases, even if there is a possible interaction between two medicines your doctor may advise you to take them together after adjusting the dose or issuing precautions.

Using rifaximin together with the following medicine is not usually recommended. Inform your doctor if you are using Eliglustat.

Other Interactions: Taking your medicine together with certain foods or items such as alcohol or tobacco may cause undesirable interactions. Talk to your doctor to know if using this medicine with food, alcohol, or tobacco is safe.

Inform your doctor about the following conditions, if any:

  • Bloody diarrhea
  • Diarrhea with fever
  • Antibiotic-induced diarrhea
  • Diarrhea caused by other microorganisms: Do not use rifaximin
  • Severe liver impairment: Use cautiously

3 Proper Usage

To use Xifaxan properly, you must follow all instructions given by your doctor.

Here are some points to consider:

  • Follow your doctor’s instructions about the use of any medicine.
  • Never discontinue or skip the dose of any antibiotic medicines without consulting your doctor. Doing so can result in recurrence of the infection.

Dosing: For best results, follow your doctor to know what amount of medicine you should take in a single dose. The doses of a medicine can differ according to the conditions for which it is being prescribed.

Remember your doses can differ. Consult your doctor if you have anything to ask. The doses of tablets are:

For the treatment of irritable bowel syndrome (IBS) accompanied by diarrhea:

  • Adults: 550 milligrams (mg) every 8 hours for 2 weeks
  • Children: Your doctor will decide the use and dose.

For the treatment of traveler's diarrhea:

  • Adults and children 12 years and above: 200 mg every 8 hours for 3 days.
  • Children below 12 years: Your doctor will decide the use and dose.

For preventing hepatic encephalopathy:

  • Adults: 550 mg two times a day.
  • Children: Your doctor will decide the use and dose.

Missed Dose: Take your missed dose once you remember but avoid it if it’s time to take your next dose, and follow your normal dosing schedule. Avoid taking double doses to make up for the missed dose.


  • Store in a closed container at room temperature.
  • Keep away from heat, moisture, and direct light.
  • Do not freeze.
  • Keep away from children.
  • Discard any unused or expired medicines.

4 Precautions to Take

Before using Xifaxan, there are some precautions you must take. Your progress should be regularly monitored to determine if you are responding to the treatment. Remember:

See your doctor immediately if diarrhea continues even after taking the medicine for 1 or 2 days, or if you have a fever or notice blood in your stool.

You can become dehydrated if you have continuous diarrhea. Drink enough fluids to prevent dehydration.

Symptoms such as decreased urinary frequency or volume, dizziness, dryness of mouth, increased thirst could indicate severe dehydration. See your doctor immediately if you notice any of these symptoms.

Consult your doctor before taking any prescription or nonprescription medicines and herbal or vitamin supplements.

5 Potential Side Effects

Make sure you meet with your doctor in using Xifaxan to avoid unwanted potential side effects.

Consult your doctor immediately if you experience any of the following side effects:

More common: 

  • Black, tar-like stools
  • Dizziness
  • Abnormal muscle contraction
  • Fast, shallow breathing
  • Sleep difficulties

Less common:

  • Bloody urine
  • Nosebleeds
  • Chest pain
  • Hearing abnormal sounds like ringing or buzzing
  • Loss of consciousness
  • Head spinning
  • Rapid heartbeat
  • Depressed eyes
  • Abnormal bleeding or bruising
  • Excessive tiredness

Mild and non-serious side effects usually go away on their own without requiring medical intervention. You may also ask your doctor to learn more about how you may prevent or reduce the side effects.

Talk to your doctor if the side effects persist or worry you, including:

More common:

  • Abdominal bloating and pain
  • Fever
  • Headache
  • Increased frequency of defecation
  • Pain in lower back or side
  • Muscle soreness or stiffness
  • Painful joints
  • Flatulence
  • Difficulty passing stool
  • Swollen hands, ankles, feet, or lower legs

Less common: 

  • Abnormal dreams
  • Blurry vision
  • Chills
  • Confusion
  • Cough
  • Reduced urinary frequency or volume
  • Dizziness
  • Fainting
  • Feeling dizzy when changing position
  • Dryness of lips and mouth
  • Earache
  • Hearing impairment
  • Decreased appetite
  • Taste changes
  • Nausea and vomiting
  • Pain while urinating
  • Pale or red skin
  • Sore throat
  • Sweating
  • Swelling of glands
  • Increased thirst
  • Wrinkles on the skin

The side effects of the medicine are not limited to the ones listed above. Call your doctor immediately if you experience any side effects that are uncommon or worry you. To report side effects to the FDA, contact at 1-800-FDA-1088.

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