Complete UrinaryExcretionProfileof 5-Fluorouracilduringa Six-Day ChemotherapeuticSchedule,as Resolved by 19FNuclearMagnetic Resonance

We determined the urinary excretion of 5-fluorouracll (5FU) and its metabolites dunng six days of chemotherapy, using the non-invasive approach of 19F nuclear magnetic resonance. With thismethod,whichrequiresno labeleddrug,one can study the biological sample directly and simultaneously Identify and quantifyall the fluorinatedmetabolites.The daily urinary excretionof 5FU and its metaboliteswas high (94.8% of 5FU administered) and nearly constant all during the treatment. By far the majorexcreted catabolite was a-fluorop-alanlne, which made up 78.9% of the total. Unchanged 5FU (10.8% of dose injected)was found only duringthe first 2 h after injection.We observed neitheraccumulationof 5FU nor modificationsin its metabolismduring the treatment. Addftlonal Keyphrases: cancer urine a-fluoro..�-aIanine metabolites