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Rifaximin Dosage

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Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Traveler's Diarrhea

200 mg orally 3 times a day for 3 days

Usual Adult Dose for Hepatic Encephalopathy

550 mg orally twice a day

Usual Pediatric Dose for Traveler's Diarrhea

12 years or older: 200 mg orally 3 times a day for 3 days

Renal Dose Adjustments

Data not available

Liver Dose Adjustments

No adjustment recommended. The manufacturer recommends caution when administering this drug to patients with severe liver dysfunction (Child-Pugh C).


Rifaximin should not be used in patients with diarrhea complicated by fever and/or blood in the stool or with travelers' diarrhea caused by pathogens other than Escherichia coli. The effectiveness against travelers' diarrhea caused by Shigella species and Salmonella species has not been proven. Rifaximin is not effective in travelers' diarrhea due to Campylobacter jejuni.

Rifaximin should be discontinued if diarrhea symptoms get worse or persist for more than 24 to 48 hours and alternative antibiotic therapy should be considered.

Clostridium difficile associated diarrhea (CDAD) has been reported with almost all antibiotics and may potentially be life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea following rifaximin therapy. Mild cases generally improve with discontinuation of the drug, while severe cases may require supportive therapy and treatment with an antimicrobial agent effective against C difficile. Hypertoxin producing strains of C difficile cause increased morbidity and mortality; these infections can be resistant to antimicrobial treatment and may necessitate colectomy.

Safety and effectiveness for travelers' diarrhea have not been established in pediatric patients less than 12 years of age. Safety and effectiveness for hepatic encephalopathy have not been established in pediatric patients less than 18 years of age.


Data not available

Other Comments

Rifaximin can be taken orally with or without food.