Xifaxan® (rifaximin)

Xifaxan® contains the active ingredient rifaximin, a non-absorbable antibiotic that acts almost exclusively in the intestine. It is used for the treatment of traveler's diarrhea (travel-associated diarrhea), particularly when caused by enterotoxigenic E. coli (ETEC).

Although Xifaxan® is primarily used for traveler's diarrhea, the 550 mg strength is also approved for reducing the recurrence of episodes of overt hepatic encephalopathy in adults. The particular advantage: because rifaximin is barely absorbed into the blood, systemic side effects are very rare.

Mechanism of action:

• Inhibits bacterial RNA synthesis by binding to the beta subunit of DNA-dependent RNA polymerase
• Has a bactericidal effect against a broad spectrum of gram-positive and gram-negative intestinal bacteria
• Virtually no systemic absorption (< 1% is absorbed)

Advantages of the local action:

• High concentrations directly in the intestine
• Hardly any systemic side effects
• Little disruption of the normal intestinal flora
• No resistance problems at the systemic level

Spectrum of activity: Efficacy has been clinically demonstrated against the most common pathogens causing traveler's diarrhea: enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC). Rifaximin has no clinical efficacy against invasive pathogenic bacteria.

Xifaxan® is suitable for:

• Treatment of uncomplicated traveler's diarrhea
• Adults aged 18 and over

Not suitable for:

• Severe, bloody diarrhea (dysentery) → systemic antibiotic needed
• Diarrhea with high fever
• Diarrhea caused by parasites (e.g., Giardia, amoebae)
• Children and adolescents under 18 years of age (insufficient data)
• Hypersensitivity to rifaximin or rifamycins

Traveler's diarrhea treatment:

• 200 mg three times daily for 3 days

Available strengths:

• 200 mg, 550 mg film-coated tablets

Hepatic encephalopathy (other indication):

• 550 mg twice daily as long-term therapy

How to take:

• Take with or without food
• Swallow the tablets whole
• Keep regular intervals between doses

Important notes:

• If your condition worsens despite treatment (fever, bloody stools), see a doctor immediately
• Follow hygiene measures
• Take in enough fluids and electrolytes if you have diarrhea
• For traveler's diarrhea, do not take for longer than 3 days unless your doctor has prescribed otherwise
• If symptoms last longer than 3 days, see a doctor

Xifaxan® must not be taken in cases of:

• Hypersensitivity to rifaximin or other rifamycin derivatives
• Intestinal obstruction

Caution in cases of:

• Severe liver dysfunction (in hepatic encephalopathy: under monitoring)
• Pregnancy and breastfeeding (insufficient data)
• Concomitant use of P-glycoprotein inhibitors (e.g., cyclosporine)

Common (1–10%):

• Headache
• Flatulence
• Abdominal pain
• Nausea
• Constipation

Uncommon (0.1–1%):

• Dizziness
• Skin rash
• Fever
• Muscle pain

Rare:

• C. difficile infection (possible despite the local action)
• Allergic reactions

General: In studies, gastrointestinal complaints occurred as often with Xifaxan® as with a dummy medication (placebo). Severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis) have been reported and can be life-threatening or fatal. If signs of such a skin reaction appear, Xifaxan® must be stopped immediately.