A drug used in the emergency treatment of patients who receive too much fluorouracil or capecitabine (types of anticancer drugs). It is also used in the emergency treatment of heart or central nervous system (CNS) toxicity or other serious side effects that occur within 4 days of ending treatment with fluorouracil or capecitabine. Vistogard may help protect healthy cells from some of the side effects caused by certain anticancer drugs. It is a type of cytoprotective agent. Also called PN401, triacetyluridine, and uridine triacetate.