Identification of minor metabolites of 5-fluorocytosine in man by chemical ionization gas chromatography mass spectrometry.
A new minor metabolite of 5-fluorocytosine, 5-hydroxy-5-fluorocytosine, was found in the urinary gravel excreted by a patient being treated with this drug. A metabolite of 5-fluorocytosine in animals, alpha-fluoro-beta-alanine, was identified and quantitated in the urine of nine patients. In general, alpha-fluoro-beta-alanine represented 0.05--0.25% of the daily dose of 5-fluorocytosine, both for orally and intravenously administered drug. Minor metabolites have been implicated in the occasional toxicity observed in patients receiving 5-fluorocytosine.
D001711:Biotransformation; D003596:Cytosine / Q000031:analogs & derivatives*; D005437:Flucytosine / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006801:Humans
D003596:Cytosine; D005437:Flucytosine