The chemical Ondansetron has a designated molecular formula of C18H19N3O and a molecular weight of 293.370 g/mol. Synonyms may include: BRN 3622981, GR 38032, GR 38032X, 1,2,3,9-Tetrahydro-9-methyl-3-((2-methyl-1H-imidazol-1-yl)methyl)-4H-carbazol-4-one, Zofran, Zofran ODT, Zophren, Zudan, UNII-4AF302ESOS, Odansetron [common misspelling of ondansetron], Zuplenz, Ondansetron Injection (ChemID). Ondansetron has been assigned a MeSH pharmacological action of: Serotonin Antagonist.