title: Feasibility of measuring 5-fluorouracil catabolic potential by oral loading.
abstract: The efficacy of 5-fluorouracil (5-FU) treatment and the incidence of adverse events differ among patients and depend to some extent on individual variations in drug catabolism. This feasibility study aimed to determine the optimum conditions for a 5-FU oral load test, which would allow the simple evaluation of individual differences in 5-FU catabolism. Patients with colon cancer were given oral 5-FU (200 mg/day) for 3 days (n = 36) or a single 100 mg dose (n = 14). Serum concentrations of uracil, dihydrouracil, 5-FU and 5-fluoro-5,6-dihydrouracil were measured before and after 5-FU administration. The results suggested that a decline in 5-FU metabolism was associated with continuous administration and increasing age. We conclude that a continuous load of 5-FU is necessary in order to predict the efficacy and side-effects of the drug. The 3-day regimen, with its ease of administration, merits further study to assess its possible clinical application.
authors.affiliation: The Department of Coloproctological Surgery, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Watabe
authors.forename: H
authors.initials: H
authors.lastname: Sengoku
authors.forename: K
authors.initials: K
authors.lastname: Kawai
authors.forename: M
authors.initials: M
authors.lastname: Matsuda
authors.forename: K
authors.initials: K
authors.lastname: Sakamoto
authors.forename: T
authors.initials: T
authors.lastname: Kamano
mesh_terms: D000284:Administration, Oral; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000473:pathology; D005472:Fluorouracil / Q000008:administration & dosage* / Q000493:pharmacokinetics* / Q000627:therapeutic use; D006801:Humans; D014498:Uracil / Q000097:blood
chemical_list: D000964:Antimetabolites, Antineoplastic; D014498:Uracil; D005472:Fluorouracil