Excretion of doxifluridine catabolites in human bile assessed by 19F NMR spectrometry.

The biliary excretion of doxifluridine (5'dFUR) catabolites was studied in a patient with external bile derivation using 19F NMR spectrometry, alpha-fluoro-beta-alanine (FBAL) and fluoride ion were detected in patient's bile samples but represented only about 10% of the excreted fluorinated metabolites. The major biliary metabolite (congruent to 90%), whose structure is still unknown, is a conjugate of FBAL. The cumulative biliary excretion of 5'dFUR fluorinated metabolites was low and represented 0.8% of the injected dose.