rifaximin alpha

Rifaximin alpha is the alpha polymorph of rifaximin, a non-absorbable, rifamycin-derived small-molecule antibiotic that acts locally in the intestinal lumen to modulate the gut microbiota and reduce pathogen-derived toxins. It inhibits bacterial RNA synthesis by binding irreversibly to the β-subunit of the bacterial DNA-dependent RNA polymerase, thereby blocking transcription and exerting broad-spectrum activity against gram-positive and gram-negative, aerobic and anaerobic bacteria while remaining minimally absorbed from the gastrointestinal tract. Clinically, rifaximin alpha has been extensively studied and used in hepatic cirrhosis—particularly for prevention and treatment of hepatic encephalopathy—and is being investigated as a disease-modifying agent in chronic liver diseases (including alcoholic liver disease and non-alcoholic steatohepatitis) through effects on intestinal permeability, bacterial translocation, inflammatory pathways, and activation of intestinal pregnane X receptor. It is also used more broadly as rifaximin for indications such as travelers’ diarrhea and irritable bowel syndrome with diarrhea, where its local antimicrobial and anti-inflammatory actions in the gut are therapeutically relevant.

Brand names

Xifaxan

Other names

rifaximin alfarifaximin αrifaximin