XIFAXAN/ZAXINE (Rifaximin)

What is this medication?

XIFAXAN/ZAXINE (Rifaximin)
Rifamycin

Brand Name US: Xifaxan
Canadian Equivalent: Zaxine

XIFAXAN/ZAXINE (Rifaximin) is officially indicated to treat hepatic encephalopathy, irritable bowel syndrome without constipation, and traveler’s diarrhea.  It is also prescribed off-label for use in clostridioides difficile infection and small intestinal bacterial overgrowth (SIBO).

How does this medication work?

XIFAXAN/ZAXINE (Rifaximin) inhibits bacterial RNA synthesis by binding to bacterial DNA-dependent RNA polymerase.

How should I take this medication?

Clostridioides Difficile Infection (Second or Recurrent)
Oral: Take 400mg three times daily for 20 days; administer after taking a 10-day course of vancomycin.

Hepatic Encephalopathy
Oral: Take 400mg three times daily or 550mg twice daily for 5 to 10 days.

Irritable Bowel Syndrome (without constipation)
Oral: Take 550mg three times daily for 14 days.

Small Intestinal Bacterial Overgrowth (SIBO)
Oral: Take 550mg three times daily for 14 days.  For patients with methane-predominant bacterial overgrowth, some experts use rifaximin as part of an appropriate combination regimen.

Travellers Diarrhea
Oral: Take 200mg three times daily for 3 days.  Avoid in patients with fever or bloody diarrhea.

How to Take: Can be taken with or without food. 

What should I watch for while using this medication?

Before starting XIFAXAN/ZAXINE (Rifaximin), make sure your physician is aware of any allergies or medications you currently take. Prolonged use may result in fungal or bacterial superinfection, including Clostridioides difficile-associated diarrhea (CDAD) and pseudomembranous colitis. Avoid using if you have diarrhea with fever and/or blood in the stool.  You need to consider alternative therapy if symptoms persist or worsen after 1 to 2 days of treatment.  Use with caution in cases with severe hepatic impairment.

What if I miss a dose?

If you miss a dose of medication, try to take it as soon as possible.  However, if it is almost time for your next dose, take only that scheduled dose.  Do not take double or extra doses.

How should I store this medication?

Keep out of the reach of children at all times.  Store at room temperature, 59 to 86° F (15 to 30° C).  Protect from light.  Keep the container tightly closed.  Properly dispose of any unused medication after the expiration date.

What are the possible side effects of using this medication?

Peripheral edema, dizziness, fatigue, ascites, nausea, irritable bowel syndrome with diarrhea.

Note this is not a complete list of side effects for XIFAXAN/ZAXINE (Rifaximin), only common ones.