Serum concentrations of 5-FU, ftorafur, and a major serum metabolite following ftorafur chemotherapy.

Abstract

Daily 24-hour serum levels of ftorafur (FT), 5-FU, and a major FT metabolite, dehydroftorafur (DFT), were monitored by high-performance liquid chromatography as part of a phase I study designed to evaluate FT as a radiosensitizing 5-FU pro-drug in patients with advanced gastrointestinal cancers. At a daily iv bolus FT dose of 1.0 g/m2, 5-FU was not detected in serum concentrations above the reliable assay limits of approximately 25 ng/ml; FT did not generate the extracellular (serum) 5-FU concentrations required for sensitization by 5-FU per se. DFT was present in every patient serum tested and was confirmed to be a metabolite of FT by in vitro conversion to 5-FU. Chemical ionization solid-probe mass spectrometry of the DFT metabolite indicates the dehydro FT structure proposed by other researchers. In six of eight patients monitored, a consistent relationship was noted between serum levels of FT and DFT.

• Authors: C L Hornbeck, J C Griffiths, R A Floyd, N C Ginther, J E Byfield, T R Sharp
• Journal: Cancer treatment reports (Cancer Treat Rep) 1981 Jan-Feb Vol. 65 Issue 1-2 Pg. 69-72 ISSN: 0361-5960 [Print] United States
• PMID: 6784923 (Publication Type: Journal Article)

Chemical References

• Tegafur
• dehydroftorafur
• Fluorouracil

Topics

• Chromatography, High Pressure Liquid
• Drug Evaluation
• Fluorouracil (analogs & derivatives, blood)
• Gastrointestinal Neoplasms (drug therapy)
• Humans
• Injections, Intravenous
• Tegafur (analogs & derivatives, blood, therapeutic use)