Rifaximin

What it is and how it works

Mechanism of Action Rifaximin is an antibacterial drug .

Indications

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. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. XIFAXAN is a rifamycin antibacterial indicated for: • 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.

Dosage and administration (summary)

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

Contraindications

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. )

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.

Pregnancy

Pregnancy Risk Summary 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 t…

Storage and supply

The 550 mg tablet is a pink-colored, oval, biconvex tablet with “rfx” debossed on one side and plain on the other. It is available in the following presentations: Bottles of approximately 360 tablets, NDC 55154-6777-8 Storage Store XIFAXAN Tablets at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) .

Source: Rifaximin (Xifaxan) — US FDA prescribing information, 2025-08-27, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.