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Everything You Need to Know About Xifaxan

Tuesday 30 January 2024
5 minute(s) read

Table of Contents

I. What is Xifaxan?

II. How Does Xifaxan Work

III. Xifaxan Dosage

IV. How To Take Xifaxan

V. Benefits of Xifaxan

VI. Xifaxan Side Effects

VII. Xifaxan During Pregnancy

VIII. Important Drug Interactions

IX. Conclusion


If you've been grappling with traveler's diarrhea or dealing with hepatic encephalopathy or IBS-D, chances are Xifaxan has crossed your radar—an antibiotic that has gained popularity for effectively treating these conditions.

This article will cover everything you need to know about Xifaxan, from how Xifaxan works to its benefits, side effects, dosages, and more. We aim to equip you with comprehensive knowledge about this medication.

What is Xifaxan?

Approved by the FDA in 2004, Xifaxan is an antibiotic designed to treat bacterial infections. [1] It is typically prescribed for:

  • Traveler’s diarrhea caused by E. coli in adults and children 12 years and older
  • Hepatic encephalopathy in adults
  • Irritable bowel syndrome with diarrhea (IBS-D) in adults [1]

It's crucial to note that Xifaxan is unsuitable for diarrhea accompanied by fever or blood in the stool. It should not be used if diarrhea is caused by bacteria other than E. coli. [1]

How Does Xifaxan work?

Four E. coli bacteria moving together

The active ingredient in Xifaxan is an antibiotic called rifaximin. This antibiotic stops bacteria from growing and surviving by blocking their ability to produce proteins. [1]

Let's break down the science behind this.

Bacteria depend on an enzyme called "RNA polymerase" to translate the genetic code in their DNA into proteins necessary for survival and growth. Rifaximin attaches to RNA polymerase and blocks it from converting the DNA code into protein. [1]

Xifaxan Dosage

Xifaxan is available in tablet form with 200 mg and 550 mg dosages. [1]

The dosage depends on why you need Xifaxan. As a guide, we’ll include FDA-approved dosages below. However, your doctor will ultimately decide which dose is right for you.

  • For traveler's diarrhea, take 200 mg of Xifaxan thrice daily for three days.
  • For hepatic encephalopathy in adults, take 550 mg twice a day.
  • For IBS-D in adults, take 550 mg of Xifaxan three times a day for fourteen days. If the first round does not work, your physician may prescribe up to two more rounds at the same dosage. [1]

How To Take Xifaxan

Daily pill box divided into morning and evening

Take Xifaxan orally as prescribed, with or without food. Try to take the medication at evenly spaced times. [1]

To help clear up the infection, take Xifaxan for the full time it’s prescribed, even if you begin to feel better after a few days. If you stop taking Xifaxan too early, the infection may return. [1]

Benefits of Xifaxan

Studies performed on the efficacy of Xifaxan showed positive results for traveler’s diarrhea, hepatic encephalopathy, and IBS-D. The FDA also supported the results. [1]

Traveler’s Diarrhea

In two studies examining Xifaxan usage for traveler's diarrhea caused by E. coli, participants were administered 200 mg of Xifaxan thrice daily for three days. Researchers analyzed the time it took for participants to return to normal, symptom-free status. The results showed that Xifaxan could reduce the duration of diarrhea experienced by participants. [1]

Hepatic Encephalopathy

A 6-month study evaluating Xifaxan's impact on hepatic encephalopathy involved participants taking 550 mg of Xifaxan twice daily. The study revealed a remarkable 58% decrease in risks associated with hepatic encephalopathy during the 6-month period. Additionally, Xifaxan usage resulted in a 50% reduction in hospitalizations related to hepatic encephalopathy. [1]

Irritable Bowel Syndrome with Diarrhea (IBS-D)

In three trials examining Xifaxan's efficacy for IBS-D, 624 participants received 550 mg of Xifaxan three times a day for fourteen days. After treatment, participants reported improvements in IBS-D symptoms. Specifically, 166 participants experienced decreased abdominal pain, 170 noted improved stool consistency, and 125 reported improvements in both abdominal pain and stool consistency. [1]

Xifaxan Side Effects

Like any medication, Xifaxan can cause side effects, although not everyone experiences them. We’ve included some common side effects below.

  • Traveler’s diarrhea: headaches
  • Hepatic encephalopathy: swelling in the lower limbs, nausea, dizziness, fatigue, or fluid buildup in the abdomen.
  • IBS-D: nausea or increased liver enzymes such as alanine transaminase (ALT). [1]

If you experience any of these side effects, it’s crucial to let your physician know.

Xifaxan During Pregnancy

pregnant woman talking to a doctor

Currently, there isn’t sufficient research on the effects of Xifaxan usage on human pregnancy. However, animal studies performed on pregnant rabbits and rats showed an increased risk of miscarriage, stillbirth, and congenital disabilities with Xifaxan usage. [1]

For this reason, the FDA advises physicians to let pregnant mothers know of the potential risks of Xifaxan on the fetus. [1]

Important Drug Interactions

When starting any medication, you must inform your doctor of any other medications you are taking. Xifaxan has two important drug interactions that you should bring to your doctor's attention.

First, if you’re taking P-glycoprotein inhibitors (such as cyclosporine), this can increase your body’s exposure to Xifaxan. In this case, your physician will monitor you more closely during treatment. {{1}

Second, adding Xifaxan may change your international normalized ratio (INR) if you're taking warfarin. This value measures the time it takes for your blood to clot. In this case, your physician will monitor your INR more closely during Xifaxan treatment and may adjust your warfarin dosage to ensure your INR stays within the target range. [1]


Xifaxan is a valuable antibiotic in treating traveler's diarrhea, hepatic encephalopathy, and IBS-D. [1]

However, as with any medication, it’s important to be aware of side effects and potential drug interactions. Let your physician know if you experience any unusual symptoms during treatment.

If you’re ready to purchase Xifaxan from Canada Pharmacy Depot, visit the medication page for pricing information. If you have any questions, contact our friendly customer care team.


What is Xifaxan used for?

Xifaxan is an antibiotic that was FDA-approved in 2004 to treat traveler’s diarrhea, hepatic encephalopathy, and IBS-D. [1]

What dosage of Xifaxan should I take?

The dosage of Xifaxan you’re prescribed depends on the condition being treated. For traveler’s diarrhea, take 200 mg three times a day for three days. For hepatic encephalopathy, take 550 mg twice a day. For IBS-D, take 550 mg three times a day for fourteen days. [1]

Does Xifaxan have any side effects?

Like any medication, Xifaxan may cause side effects in some people. You may experience headaches, swelling in the lower limbs, nausea, dizziness, fatigue, fluid buildup in the abdomen, or increased liver enzymes such as alanine transaminase (ALT). [1] For a complete list of side effects, please contact your doctor.

The content provided in this article is based on thorough research and in some cases, reviewed by a medical professional. Our goal for the information is to provide helpful, general health informational. It is not intended as a substitute for professional medical advice.