Rifaximin

Molecular Formula: C43H51N3O11
CAS Number: 80621-81-4
Appearance: Red-orange crystalline powder

is an antibiotic used to treat traveler’s diarrhea, irritable bowel syndrome, and hepatic encephalopathy. It has poor absorption when taken by mouth. It is based on rifamycin. Rifaximin is a semi-synthetic derivative of rifampin and acts by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase blocking one of the steps in transcription. This results in inhibition of bacterial protein synthesis and consequently inhibits the growth of bacteria. This medication is used to treat diarrhea caused by the common bacteria known as E. coli (“traveler’s diarrhea”). Rifaximin should not be used if you have a fever or bloody diarrhea. It works by stopping the growth of bacteria. This antibiotic treats only bacterial infections.