title: [Relationship of plasma concentration of 5-fluorouracil with toxicity and response in patients with nasopharyngeal carcinoma].
abstract: OBJECTIVE
  Because there are several mechanisms of activity and toxicity and inter-individual variation in pharmaco- dynamics of 5-fluorouracil (5-FU),it is difficult to predict the sensitivity and toxicity of 5-FU in an individual patient. This study was designed to assess inter-patient variation of 5-FU steady-state plasma concentration and the relationship of plasma concentration of 5-FU with toxic side effects and therapeutic response.
  
  
  METHODS
  Twenty patients with nasopharyngeal carcinoma were treated with 5-FU combined with cisplatin(DDP). Blood samples were collected after 24 hours of infusion of 5-FU. Plasma concentrations of 5-FU were measured using high performance liquid chromatography(HPLC) with column temperature at 25 Celsius degree, flow rate at 1.3 ml/min, wave length at 260 nm and 1 mmol/l phosphate buffer (pH 3.0) as mobile phase.
  
  
  RESULTS
  The plasma concentrations of 5-FU were normally distributed in the patients. No adverse effects were noted in the patients with plasma concentration of 5-FU lower than 600 microg/L, and severe toxic side effects were observed in the patients with plasma concentration of 5-FU greater than 1000 microg/L. The differences between plasma concentrations of 5-FU and each grade side effects reached statistical significance (P< 0.05).
  
  
  CONCLUSIONS
  The plasma concentration of 5-FU have highly inter-individual variation in the patients with nasopharyngeal carcinoma. Plasma concentrations of 5-FU were associated with the toxicity and treatment response.
authors.affiliation: Department of Oncology, Jiangmen Central Hospital, Jiangmen, Guangdong, PR China. gs-yu@21cn.com
authors.forename: Geng-Sheng
authors.initials: GS
authors.lastname: Yu
authors.forename: You-Jian
authors.initials: YJ
authors.lastname: He
authors.forename: Hai
authors.initials: H
authors.lastname: Liao
authors.forename: Su
authors.initials: S
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D005472:Fluorouracil / Q000009:adverse effects / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000097:blood*; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D005472:Fluorouracil