What are the uses and dosages of Xifaxan (rifaximin)?

From the Guidelines

Xifaxan (rifaximin) is primarily used to treat traveler's diarrhea, hepatic encephalopathy, and irritable bowel syndrome with diarrhea (IBS-D), with specific dosages for each condition, including 550 mg three times daily for 14 days for IBS-D, as supported by a meta-analysis of 2 RCTs recruiting 1260 patients 1. The uses and dosages of Xifaxan (rifaximin) are as follows:

• For traveler's diarrhea caused by non-invasive E. coli in patients 12 years and older, the recommended dosage is 200 mg three times daily for 3 days.
• For hepatic encephalopathy in adults, the dosage is 550 mg twice daily to reduce the risk of recurrence.
• For irritable bowel syndrome with diarrhea (IBS-D) in adults, the dosage is 550 mg three times daily for 14 days, with the possibility of repeating the course up to two more times if symptoms recur, as shown in a study where significantly more patients experienced an improvement in global symptoms with rifaximin after each treatment course 1. Key points to consider when using Xifaxan include:
• The medication works by inhibiting bacterial RNA synthesis and is minimally absorbed systemically, allowing it to target intestinal bacteria while minimizing systemic side effects.
• Common side effects include nausea, bloating, and headache, with headache being the most common adverse event in IBS-D trials 1.
• Patients should complete the full course of treatment even if symptoms improve before completion.
• Xifaxan should not be used for diarrhea with fever or blood in stool, or in patients with known hypersensitivity to rifaximin or rifamycin antimicrobial agents.
• It's essential to take the medication with or without food as prescribed and inform healthcare providers of all other medications being taken to avoid potential interactions.

From the FDA Drug Label

1 INDICATIONS AND USAGE

To reduce the development of drug-resistant bacteria and maintain the effectiveness of XIFAXAN and other antibacterial drugs, XIFAXAN when used to treat infection should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria

1. 1 Travelers’ Diarrhea XIFAXAN is indicated for the treatment of travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli in adults and pediatric patients 12 years of age and older
2. 2 Hepatic Encephalopathy XIFAXAN is indicated for reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults.
3. 3 Irritable Bowel Syndrome with Diarrhea XIFAXAN is indicated for the treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults.

2 DOSAGE AND ADMINISTRATION

2.1 Dosage for Travelers’ Diarrhea The recommended dose of XIFAXAN is one 200 mg tablet taken orally three times a day for 3 days. 2.2 Dosage for Hepatic Encephalopathy The recommended dose of XIFAXAN is one 550 mg tablet taken orally two times a day. 2.3 Dosage for Irritable Bowel Syndrome with Diarrhea The recommended dose of XIFAXAN is one 550 mg tablet taken orally three times a day for 14 days.

The uses of Xifaxan (rifaximin) are:

• Treatment of travelers’ diarrhea (TD) caused by noninvasive strains of Escherichia coli in adults and pediatric patients 12 years of age and older
• Reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults
• Treatment of irritable bowel syndrome with diarrhea (IBS-D) in adults

The dosages of Xifaxan (rifaximin) are:

• Travelers’ diarrhea: 200 mg orally three times a day for 3 days
• Hepatic encephalopathy: 550 mg orally two times a day
• Irritable bowel syndrome with diarrhea: 550 mg orally three times a day for 14 days 2 2

From the Research

Uses of Xifaxan (Rifaximin)

• Xifaxan is used to treat travelers' diarrhea caused by noninvasive diarrheagenic Escherichia coli 3, 4, 5
• It is also used to prevent hepatic encephalopathy recurrence 3, 6
• Xifaxan is effective in treating diarrhea-predominant irritable bowel syndrome (IBS) 3, 7
• It may be useful in other gastrointestinal diseases, such as small bowel bacterial overgrowth, inflammatory bowel disease, and pouchitis 4, 6, 5

Dosages of Xifaxan (Rifaximin)

• For travelers' diarrhea, the dosage is 600 mg/d 3
• For the prevention of hepatic encephalopathy recurrence, the dosage is 1100 mg/d 3
• For diarrhea-predominant IBS, the dosage is 1650 mg/d for 2 weeks 3, 7
• The dosage may vary depending on the specific condition being treated and the patient's response to the medication 4, 6, 5

Mechanisms of Action

• Xifaxan appears to reduce bacterial virulence and pathogenicity by inhibiting bacterial translocation across the gastrointestinal epithelial lining 3
• It also modulates gut-immune signaling and has cytoprotection properties 3, 6
• The exact mechanisms of action are not fully understood and may involve multiple pathways 3, 4, 6