Rifaximin Dosage

Medically reviewed by Drugs.com. Last updated on Mar 24, 2025.

Applies to the following strengths: 550 mg; 200 mg

Usual Adult Dose for Traveler's Diarrhea

200 mg orally 3 times a day for 3 days

Comments:

This drug should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea caused by pathogens other than Escherichia coli.

Use: For the treatment of travelers' diarrhea due to noninvasive strains of E coli

Usual Adult Dose for Hepatic Encephalopathy

550 mg orally twice a day

Comments:

In trials, lactulose was used concomitantly in 91% of patients; differences in treatment effect of patients not using concomitant lactulose could not be assessed.

Use: For reduction in risk of overt hepatic encephalopathy recurrence

Usual Adult Dose for Irritable Bowel Syndrome

550 mg orally 3 times a day for 14 days

Comments:

If symptoms recur, patients can be retreated up to 2 times with the same dosage regimen.

Use: For the treatment of irritable bowel syndrome with diarrhea

Usual Pediatric Dose for Traveler's Diarrhea

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

Comments:

This drug should not be used in patients with diarrhea complicated by fever or blood in the stool or diarrhea caused by pathogens other than E coli.

Use: For the treatment of travelers' diarrhea due to noninvasive strains of E coli

Renal Dose Adjustments

Renal dysfunction: Data not available

Liver Dose Adjustments

Mild or moderate liver dysfunction (Child-Pugh A or B): No adjustment recommended.
Severe liver dysfunction (Child-Pugh C): Caution recommended.

Comments:

This drug was not studied in hepatic encephalopathy patients with Model for End-Stage Liver Disease (MELD) scores greater than 25; in the controlled trial, only 8.6% of patients had MELD scores over 19.
Systemic exposure increased in patients with more severe liver dysfunction.

Precautions

CONTRAINDICATIONS:
Hypersensitivity to the active component, any of the rifamycin antimicrobial agents, or any of the ingredients

Travelers' diarrhea: Safety and efficacy have not been established in patients younger than 12 years.
Hepatic encephalopathy, irritable bowel syndrome with diarrhea: Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.

Dialysis

Data not available

Other Comments

Administration advice:

Administer with or without food.

General:

To reduce the development of drug-resistant organisms and maintain effective therapy, this drug (when used to treat infection) should be used only to treat or prevent infections proven or strongly suspected to be caused by susceptible bacteria.
Culture and susceptibility information should be considered when selecting/modifying antibacterial therapy or, if no data are available, local epidemiology and susceptibility patterns may be considered when selecting empiric therapy.

Patient advice:

If using for travelers' diarrhea, seek medical attention for fever and/or blood in the stool.
Contact physician as soon as possible if diarrhea develops after therapy or does not improve/worsens during therapy.
Avoid missing doses and complete the entire course of therapy.