title: Effects of bolus injection of 5-fluorouracil on steady-state plasma concentrations of 5-fluorouracil in Japanese patients with advanced colorectal cancer.
abstract: OBJECTIVE
  The irinotecan (CPT-11) + 5-fluorouracil (5-FU)/leucovorin (LV) + UFT/LV chemotherapy, in which repetitive oral administration of UFT/LV replaces the infusion of 5-FU/LV in the FOLFIRI regimen, has been proposed previously. In this study, five of 10 patients were injected with a bolus of 5-FU and the other were not injected with it in order to examine the effect of omitting it in terms of pharmacokinetics of 5-FU.
  
  
  METHODS
  The treatment consisted of the intravenous infusions of CPT-11 at 100 mg/m(2 )and l-LV at 15 mg/m(2), and the injection of a bolus of 5-FU at 500 mg/m(2) on day 1, and the repetitive oral administration of UFT/LV (300 mg/m(2)/day as tegafur + 75 mg/day of LV) on days 1-5. A total of 13 measurements of the plasma concentrations of uracil, 5-FU and tegafur were made per patient within 48 hr after the start of chemotherapy and the value of area under the concentration-time curve (AUC(0-48)) was evaluated. The plasma concentration was also determined at 2 weeks to assess long-term exposure to 5-FU.
  
  
  RESULTS
  The plasma concentrations of 5-FU at 24 hr after the start of treatment were 27.4 ng/mL and 9.4 ng/mL in the patients with and without the bolus injection, respectively. At 48 hr, they were 31.3 ng/mL and 10.4 ng/mL with the AUC(0-48) values of 22.16 mg h/L and 0.65 mg h/L, respectively. The 5-FU was detected in the plasma at 226 hr after the last administration of UFT/LV for the patients with the bolus injection, but not for those without.
  
  
  CONCLUSIONS
  A bolus of 5-FU on day 1 provided long-term exposure to 5-FU.
authors.affiliation: Kinki University Nara Hospital, Nara 630-0293, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Tamura
authors.forename: Akiko
authors.initials: A
authors.lastname: Kuwahara
authors.forename: Kaori
authors.initials: K
authors.lastname: Kadoyama
authors.forename: Motohiro
authors.initials: M
authors.lastname: Yamamori
authors.forename: Kohshi
authors.initials: K
authors.lastname: Nishiguchi
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Inokuma
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
authors.forename: Naoko
authors.initials: N
authors.lastname: Chayahara
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okuno
authors.forename: Ikuya
authors.initials: I
authors.lastname: Miki
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Fujishima
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sakaeda
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D019540:Area Under Curve; D015179:Colorectal Neoplasms / Q000097:blood / Q000188:drug therapy*; D005472:Fluorouracil / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D007564:Japan
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil