Rifaximin

Rifaximin
Clinical data
Trade namesXifaxan, others
AHFS/Drugs.comMonograph
MedlinePlusa604027
License data
Pregnancy
category
  • AU: B1
Routes of
administration
By mouth
ATC code
Legal status
Legal status
Pharmacokinetic data
Bioavailability< 0.4%
MetabolismLiver
Elimination half-life6 hours
ExcretionFecal (97%)
Identifiers
  • (2S,16Z,18E,20S,21S,22R,23R,24R,25S,26S,27S,28E)-5,6,21,23,25-pentahydroxy-27-methoxy-2,4,11,16,20,22,24,26-octamethyl-2,7-(epoxypentadeca-[1,11,13]trienimino)benzofuro
    [4,5-e]pyrido[1,2-a]-benzimida-zole-1,15(2H)-dione,25-acetate
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard100.111.624
Chemical and physical data
FormulaC43H51N3O11
Molar mass785.891 g·mol−1
3D model (JSmol)
Melting point200 to 205 °C (392 to 401 °F) (dec.)
  • CC(=O)O[C@H]3[C@H](C)[C@H](O)[C@H](C)[C@@H](O)[C@@H](C)\C=C\C=C(\C)C(=O)Nc6c2c(nc1cc(C)ccn12)c5c4C(=O)[C@@](C)(O/C=C/[C@H](OC)[C@H]3C)Oc4c(C)c(O)c5c6O
  • InChI=1S/C43H51N3O11/c1-19-14-16-46-28(18-19)44-32-29-30-37(50)25(7)40-31(29)41(52)43(9,57-40)55-17-15-27(54-10)22(4)39(56-26(8)47)24(6)36(49)23(5)35(48)20(2)12-11-13-21(3)42(53)45-33(34(32)46)38(30)51/h11-18,20,22-24,27,35-36,39,48-51H,1-10H3,(H,45,53)/b12-11+,17-15+,21-13-/t20-,22+,23+,24+,27-,35-,36+,39+,43-/m0/s1 Y
  • Key:NZCRJKRKKOLAOJ-XRCRFVBUSA-N Y
 NY (what is this?)  (verify)

Rifaximin is a non-absorbable, broad-spectrum antibiotic mainly used to treat travelers' diarrhea. It is based on the rifamycin antibiotics family. Since its approval in Italy in 1987, it has been licensed in more than 30 countries for the treatment of a variety of non-infectious gastrointestinal diseases like irritable bowel syndrome and hepatic encephalopathy. It acts by inhibiting RNA synthesis in susceptible bacteria by binding to the RNA polymerase enzyme. This binding blocks translocation, which stops transcription. It was developed by Salix Pharmaceuticals.