Flucytosine toxicity

Prolonged high plasma levels of flucytosine cause dose related reversible bone marrow depression, alopecia. 5-FC causes reversible neutropenia, thrombocytopenia. Caution must be exercised in patients undergoing radiation or chemotherapy with drugs that depress bone marrow. Reversible hepatic dysfunction with elevation of serum transaminases and alkaline phosphatase may occur. nausea, vomiting, and diarrhea, are common, and severe enterocolitis may also occur. [Note: Some of these adverse effects may be related to 5-FU formed by intestinal organisms from 5-FC.]