ABSTRACT
Flucytosine (5-fluorocytosine; 5-FC) is low-molecular weight water-soluble synthetic fluorinated pyrimidine-analogue (Fig. 1). It is taken up into the fungal cell by the fungus-specific enzyme cytosine permease and converted in the cytoplasm by cytosine deaminase to 5-fluorouracil which causes RNA miscoding and inhibits DNA-synthesis (1). The 5-FC is relatively non-toxic to mammalian cells because of the absence or very low level of activity of cytosine deaminase. In the United States, 5-FC is available only as oral formulation; outside the United States, an IV formulation is available in select countries.
