rifaximin

Rifaximin is a non-absorbable, broad-spectrum antibiotic derived from the rifamycin class. It is primarily used to treat traveler's diarrhea caused by *Escherichia coli*, prevent hepatic encephalopathy in patients with liver disease, and manage irritable bowel syndrome with diarrhea (IBS-D)[1][2][3][4]. Rifaximin acts locally within the gastrointestinal tract due to its poor systemic absorption. Its main mechanism of action is inhibition of bacterial RNA synthesis by binding irreversibly to the beta-subunit of bacterial DNA-dependent RNA polymerase, thereby blocking transcription and reducing pathogenic bacteria populations[4][5][6]. Additional effects include modulation of gut microflora and possible anti-inflammatory activity via activation of pregnane X receptor (PXR), which may contribute to symptom relief in IBS-D[4][5]. Rifaximin was developed as a semisynthetic derivative of rifamycin.

Brand names

Xifaxan

Other names

rifaximin alpharifaximin-αrifamycin SV derivative