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Rifaximin oral tablet

Yokohama City University · FDA-approved active Small molecule

Rifaximin is a non-absorbed antibiotic that inhibits bacterial RNA polymerase to reduce pathogenic gut bacteria.

Rifaximin is a non-absorbed antibiotic that inhibits bacterial RNA polymerase to reduce pathogenic gut bacteria. Used for Traveler's diarrhea caused by non-invasive strains of Escherichia coli, Hepatic encephalopathy, Irritable bowel syndrome with diarrhea (IBS-D).

At a glance

Generic nameRifaximin oral tablet
Also known asL-105, Sugar Pill
SponsorYokohama City University
Drug classRifamycin antibiotic
TargetBacterial RNA polymerase
ModalitySmall molecule
Therapeutic areaGastroenterology / Infectious Disease
PhaseFDA-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 systemically, it achieves high local concentrations in the gut while maintaining low systemic exposure, making it suitable for treating intestinal infections and conditions driven by dysbiosis.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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