Rifaximin

Xifaxan

Approved uses

• Treatment of travelers' diarrhea (TD) caused by noninvasive strains of Escherichia coli in adult 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. Limitations of Use TD: Should not use in patients with diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli.

Forms and strengths

• 550 mg - an oval tablet debossed with "rfx" on one side and plain on the other. 200 mg and 550 mg tablets

How it is taken

• Condition Recommended Oral Dosage TD 200 mg 3 times a day for 3 days HE 550 mg 2 times a day IBS-D 550 mg 3 times a day for 14 days.
• Patients who experience recurrence can be retreated up to 2 times with the same regimen.
• XIFAXAN can be taken with or without food.

Must not be used when

• XIFAXAN is contraindicated in patients with a hypersensitivity to rifaximin, any of the rifamycin antimicrobial agents, or any of the components in XIFAXAN.
• Hypersensitivity reactions have included exfoliative dermatitis, angioneurotic edema, and anaphylaxis.
• History of hypersensitivity to rifaximin, rifamycin antimicrobial agents, or any of the components of XIFAXAN.

Interactions

• Warfarin: Monitor INR and prothrombin time; dose adjustment of warfarin may be needed to maintain target INR range.

Warnings and precautions

• Travelers' Diarrhea Not Caused by E. coli: XIFAXAN was not effective in diarrhea complicated by fever and/or blood in the stool or diarrhea due to pathogens other than E. coli. If diarrhea symptoms get worse or persist for more than 24 to 48 hours, discontinue XIFAXAN and consider alternative antibiotics.
• Clostridium difficile -Associated Diarrhea: Evaluate if diarrhea occurs after therapy or does not improve or worsens during therapy.
• Hepatic Impairment: Use with caution in patients with severe (Child-Pugh Class C) hepatic impairment.
• Concomitant P-glycoprotein (P-gp) inhibitors (e.g., cyclosporine): Caution should be exercised when concomitant use of XIFAXAN and a P-glycoprotein inhibitor is needed. Travelers' Diarrhea Not Caused by Escherichia coli XIFAXAN was not found to be effective in patients with diarrhea complicated by fever and/or blood in the stool or diarrhea due to pathogens other than Escherichia coli.

Common side effects

• Most common adverse reactions: • TD (≥2%): Headache • HE (≥10%): Peripheral edema, nausea, constipation, dizziness, fatigue, urinary tract infection, insomnia, anemia, pruritus, and ascites • IBS-D (≥2%): ALT increased, nausea To report SUSPECTED ADVERSE REACTIONS, contact Salix Pharmaceuticals at 1-800-321-4576 or FDA at 1-800-FDA-1088 or www.
• most common adverse reactions that occurred at an incidence ≥5% and at a higher incidence in XIFAXAN-treated subjects than in the placebo group in the 6-month trial are provided in Table 1.
• most common adverse reactions that occurred at an incidence ≥5% are provided in Table 2.

Pregnancy

There are no available data on XIFAXAN use in pregnant women to inform any drug-associated risks. Teratogenic effects were observed in animal reproduction studies following administration of rifaximin to pregnant rats and rabbits during organogenesis at doses approximately 0.9 to 5 times and 0.7 to 33 times, respectively of the recommended human doses of 600 mg to 1,650 mg per day.

How it acts

Rifaximin is an antibacterial drug.

Label holder:

Salix Pharmaceuticals, Inc.

Label version:

25 June 2025

This section reports the approved product information. The wording is condensed from the regulator's own summary, and the full document is linked under Sources.