Rifaximin

DRUG INFORMATION

  ADULT
    - Condition Recommended Dosage Regimen TD ( 2.1 ) One 200 mg tablet 3 times a day
      for 3 days HE ( 2.2 ) One 550 mg tablet 2 times a day IBS-D ( 2.3 ) One 550 mg
      tablet 3 times a day for 14 days.
      Source: US FDA label for rifaximin (XIFAXAN), section 'dosage and administration',
      retrieved 2026-08-29
    - Patients who experience recurrence can be retreated up to 2 times with the same
      regimen. • XIFAXAN can be taken with or without food ( 2.4 ) 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.
      Source: US FDA label for rifaximin (XIFAXAN), section 'dosage and administration',
      retrieved 2026-08-29
    - Condition Recommended Dosage Regimen TD ( 2.1 ) One 200 mg tablet 3 times a day
      for 3 days HE ( 2.2 ) One 550 mg tablet 2 times a day IBS-D ( 2.3 ) One 550 mg
      tablet 3 times a day for 14 days. Patients who experience recurrence can be
      retreated up to 2 times with the same regimen.
      Source: US FDA label for rifaximin (XIFAXAN), section 'dosage and administration',
      retrieved 2026-08-29

  CHILD
    - The safety and effectiveness of XIFAXAN has not been established in pediatric
      patients less than 12 years of age with TD or in patients less than 18 years of
      age for HE and IBS-D.
      Source: US FDA label for rifaximin (XIFAXAN), section 'pediatric use', retrieved
      2026-08-29

  RENAL IMPAIRMENT
    - Other reported clinical experience has not identified differences in responses
      between the elderly and younger patients, but greater sensitivity of some older
      individuals cannot be ruled out. 8.6 Renal Impairment The pharmacokinetics of
      rifaximin in patients with impaired renal function has not been studied.
      Source: US FDA label for rifaximin (XIFAXAN), section 'use in specific
      populations', retrieved 2026-08-29

  HEPATIC IMPAIRMENT
    - Other reported clinical experience has not identified differences in responses
      between the elderly and younger patients, but greater sensitivity of some older
      individuals cannot be ruled out. 8.6 Renal Impairment The pharmacokinetics of
      rifaximin in patients with impaired renal function has not been studied.
      Source: US FDA label for rifaximin (XIFAXAN), section 'use in specific
      populations', retrieved 2026-08-29
    - Nonetheless, caution should be exercised when XIFAXAN is administered to patients
      with severe hepatic impairment [see Warnings and Precautions ( 5.4 ), Clinical
      Pharmacology ( 12.3 ), Clinical Studies ( 14.2 )] .
      Source: US FDA label for rifaximin (XIFAXAN), section 'use in specific
      populations', retrieved 2026-08-29
    - Therefore, caution should be exercised when administering XIFAXAN to patients with
      severe hepatic impairment (Child-Pugh Class C) [see Use in Specific Populations (
      8.7 ), Clinical Studies ( 14.2 )]. 5.5 Concomitant Use with P-glycoprotein
      Inhibitors Concomitant administration of drugs that are P-glycoprotein (P-gp)
      inhibitors with XIFAXAN can substantially increase the systemic exposure to
      rifaximin.
      Source: US FDA label for rifaximin (XIFAXAN), section 'warnings and cautions',
      retrieved 2026-08-29

  PREGNANCY
    - Risk Summary There are no available data on XIFAXAN use in pregnant women to
      inform any drug-associated risks.
      Source: US FDA label for rifaximin (XIFAXAN), section 'pregnancy', retrieved
      2026-08-29
    - 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.
      Source: US FDA label for rifaximin (XIFAXAN), section 'pregnancy', retrieved
      2026-08-29
    - In rabbits, ocular, oral and maxillofacial, cardiac, and lumbar spine
      malformations were observed.
      Source: US FDA label for rifaximin (XIFAXAN), section 'pregnancy', retrieved
      2026-08-29

  BREASTFEEDING
    - A pre and postnatal development study in rats showed no evidence of any adverse
      effect on pre and postnatal development at oral doses of rifaximin up to 300 mg/kg
      per day (approximately 5 times the recommended dose for TD [600 mg per day], and
      approximately 2.6 times the recommended dose for HE [1,100 mg per day], and
      approximately 1.8 times the recommended dose for IBS-D [1,650 mg per day] adjusted
      for body surface area).
      Source: US FDA label for rifaximin (XIFAXAN), section 'use in specific
      populations', retrieved 2026-08-29
    - The development and health benefits of breastfeeding should be considered along
      with the mother’s clinical need for XIFAXAN and any potential adverse effects on
      the breastfed infant from XIFAXAN or from the underlying maternal condition. 8.4
      Pediatric Use The safety and effectiveness of XIFAXAN has not been established in
      pediatric patients less than 12 years of age with TD or in patients less than 18
      years of age for HE and IBS-D.
      Source: US FDA label for rifaximin (XIFAXAN), section 'use in specific
      populations', retrieved 2026-08-29