Synonyms: Ondansetron Hydrochloride Dihydrate Imp. D (EP), Ondansetron Imp. D (EP), Ondansetron USP Related Compound D, Ondansetron USP RC D, 9-Methyl-3-methylene-1,2,3,9-tetrahydro-4H-carbazol-4-one, GR 44122X, Ph Eur Ondansetron Impurity D, USP Ondanestron Related Compound D, ondansetron olefin (GR 44122X), Ondansetron related, Ondansetron Related Compound D, Ondansetron Hydrochloride Dihydrate Impurity D, Ondansetron Impurity D