Nucleoside metabolic inhibitors are used to treat certain cancers, blood disorders, and skin conditions. These medications work by interfering with DNA or RNA synthesis in cells. Nucleoside metabolic inhibitors come in different forms, including oral pills, injections, and creams. Examples include fluorouracil (Adrucil, Efudex, Carac), capecitabine (Xeloda), and azacitidine (Vidaza, Onureg).