Uridine Triacetate as Antidote for Patients at Excess Risk of 5-FU Toxicity Due to Overdosage or Impaired Elimination

The purpose of this study is to provide emergency treatment of adult and pediatric patients: * Following a fluorouracil or capecitabine overdose regardless of the presence of symptoms or * Who exhibit early-onset, severe or life-threatening toxicity affecting the cardiac or central nervous systems, and/or early-onset, unusually severe adverse reactions (e.g., gastrointestinal toxicity and/or neutropenia) within 96 hours following the end of fluorouracil or capecitabine administration.