The chemical Fidaxomicin has a designated molecular formula of C52H74Cl2O18 and a molecular weight of 1058.046 g/mol. Synonyms may include: Clostomicin B1, Lipiarmicin, Lipiarmycin, Lipiarmycin A 3, OPT 80, PAR 101, PAR 01, R-Tiacumicin B, Tiacumicin B, UNII-Z5N076G8YQ, BRN 5228707, Dificid (ChemID). Fidaxomicin has been assigned a MeSH pharmacological action of: Antibacterial.