TY - JOUR
T1 - 5-fluorocytosine-related bone-marrow depression and conversion to fluorouracil: a pilot study
AU - Vermes, András
AU - Guchelaar, Henk-Jan
AU - van Kuilenburg, Andre B. P.
AU - Dankert, Jacob
PY - 2002
Y1 - 2002
N2 - The aim of this study is to investigate whether fluorouracil (5-FU) could be responsible for bone-marrow depression occurring in fluorocytosine 5-FC) treated patients. Six 5-FC treated patients were included in this pilot study. Toxicity was monitored by means of thrombocyte and leucocyte counts. 5-FC and 5-FU serum levels were measured using a high-performance liquid chromatography (HPLC) assay that allows simultaneous determination of both compounds. The amounts of 5-FU in the 34 available serum samples remained below the limit of quantitation ( <0.05 mg/L), whereas 5-FC levels could be detected in all samples. Instead, low levels of the 5-FU catabolite alpha-fluoro-beta-alanine (FBAL) were detected in several of the investigated serum samples. In case of three patients thrombocyte counts remained within the normal range during 5-FC treatment, whereas one patient developed thrombocytopenia (50 x 10(9) thrombocytes/L) during therapy. Furthermore, one patient developed leucocytopenia (2.6 x 10(9) leucocytes/L) during 5-FC therapy, whereas the remaining five patients were suffering from leucocytosis prior to 5-FC therapy. In conclusion, we found nondetectable 5-FU serum concentrations ( <0.05 mg/L) in ICU patients treated with intravenous 5-FC, making it unlikely that 5-FC associated toxicity results from 5-FU exposure in patients receiving intravenous 5-FC therapy. These findings may be explained by the fact that our patients received 5-FC intravenously instead of orally, therefore not allowing active conversion of 5-FC to 5-FU by the human intestinal microflora
AB - The aim of this study is to investigate whether fluorouracil (5-FU) could be responsible for bone-marrow depression occurring in fluorocytosine 5-FC) treated patients. Six 5-FC treated patients were included in this pilot study. Toxicity was monitored by means of thrombocyte and leucocyte counts. 5-FC and 5-FU serum levels were measured using a high-performance liquid chromatography (HPLC) assay that allows simultaneous determination of both compounds. The amounts of 5-FU in the 34 available serum samples remained below the limit of quantitation ( <0.05 mg/L), whereas 5-FC levels could be detected in all samples. Instead, low levels of the 5-FU catabolite alpha-fluoro-beta-alanine (FBAL) were detected in several of the investigated serum samples. In case of three patients thrombocyte counts remained within the normal range during 5-FC treatment, whereas one patient developed thrombocytopenia (50 x 10(9) thrombocytes/L) during therapy. Furthermore, one patient developed leucocytopenia (2.6 x 10(9) leucocytes/L) during 5-FC therapy, whereas the remaining five patients were suffering from leucocytosis prior to 5-FC therapy. In conclusion, we found nondetectable 5-FU serum concentrations ( <0.05 mg/L) in ICU patients treated with intravenous 5-FC, making it unlikely that 5-FC associated toxicity results from 5-FU exposure in patients receiving intravenous 5-FC therapy. These findings may be explained by the fact that our patients received 5-FC intravenously instead of orally, therefore not allowing active conversion of 5-FC to 5-FU by the human intestinal microflora
U2 - https://doi.org/10.1046/j.1472-8206.2002.00064.x
DO - https://doi.org/10.1046/j.1472-8206.2002.00064.x
M3 - Article
C2 - 11903511
SN - 0767-3981
VL - 16
SP - 39
EP - 47
JO - Fundamental & clinical pharmacology
JF - Fundamental & clinical pharmacology
IS - 1
ER -