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Rifaximin (XIFAXAN)
Rifaximin is a non-absorbed antibiotic that inhibits bacterial RNA polymerase to reduce pathogenic gut bacteria without systemic absorption.
Rifaximin is a non-absorbed antibiotic that inhibits bacterial RNA polymerase to reduce pathogenic gut bacteria without systemic absorption. Used for Traveler's diarrhea caused by noninvasive strains of Escherichia coli, Hepatic encephalopathy (reduction of overt episodes), Irritable bowel syndrome with diarrhea (IBS-D).
At a glance
| Generic name | Rifaximin (XIFAXAN) |
|---|---|
| Also known as | XIFAXAN, Xifaxan® |
| Sponsor | University of California, San Francisco |
| Drug class | Non-absorbed rifamycin antibiotic |
| Target | Bacterial RNA polymerase |
| Modality | Small molecule |
| Therapeutic area | Gastroenterology / Infectious Disease |
| Phase | FDA-approved |
Mechanism of action
Rifaximin is a rifamycin-class antibiotic that acts locally in the gastrointestinal tract by inhibiting bacterial RNA polymerase, thereby suppressing the growth of gram-positive and gram-negative enteric bacteria. Because it is minimally absorbed from the GI tract, it achieves high local concentrations in the gut while maintaining low systemic exposure, making it suitable for treating local GI infections and conditions driven by dysbiosis.
Approved indications
- Traveler's diarrhea caused by noninvasive strains of Escherichia coli
- Hepatic encephalopathy (reduction of overt episodes)
- Irritable bowel syndrome with diarrhea (IBS-D)
Common side effects
- Abdominal pain
- Diarrhea
- Nausea
- Flatulence
- Headache
Key clinical trials
- Rifaximin 200 mg Plus Oral Rehydration vs Oral Rehydration Alone in Children With Acute Diarrhea (PHASE4)
- Pharmacokinetic Study of Single-Dose Modified Release Glipizide in Healthy Volunteers (PHASE1)
- Evaluation of the Outcome of Fecal Microbiota Transplantation (PHASE1, PHASE2)
- Mechanical Bowel Preparation With or Without Oral Antibiotics in Left Sided Colorectal Cancer Surgery (NA)
- Effect of Multispecies Probiotic Supplementation on the Efficacy of Rifaximin α Therapy in Patients With Small Intestinal Bacterial Overgrowth (SIBO): a Randomized Placebo-controlled Trial (PHASE4)
- Efficacy and Safety of Early Initiation of Midodrine for Control and Prevention of Ascites and Its Related Complications in Acute-on-chronic Liver Failure. (NA)
- Efficacy and Safety of Rifaximin-α in Treating MASLD (EARLY_PHASE1)
- Rifaximin Versus No Intervention for the Treatment of IgA Monoclonal Gammopathy of Undetermined Significance (PHASE2)
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| ClinicalTrials.gov | Trial enrolment, design, endpoints, results |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Rifaximin (XIFAXAN) CI brief — competitive landscape report
- Rifaximin (XIFAXAN) updates RSS · CI watch RSS
- University of California, San Francisco portfolio CI