title: Hair analysis of flecainide for assessing the individual drug-taking behavior.
abstract: OBJECTIVE
  The concentration of flecainide in hair was measured to determine its value as an index of individual drug-taking history.
  
  
  METHODS
  Hair samples obtained from 15 patients treated with flecainide for more than 1 month were cut into 1-cm-long portions successively from its scalp end. The concentration of flecainide in each hair portion was measured using high-performance liquid chromatography.
  
  
  RESULTS
  Flecainide was detected in the 1-cm-long hair portion at the scalp end in the concentration range of 38.0-411.9 ng x mg(-1), which significantly correlated with the area under the plasma flecainide concentration versus time curve. The axial centimeter-by-centimeter distribution of flecainide along the hair shaft well reflected the individual history of drug use.
  
  
  CONCLUSIONS
  The present study suggests the usefulness of determining flecainide in hair to provide retrospective information on the individual drug-taking behavior qualitatively.
authors.affiliation: Department of Clinical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokushima, 1-78 Sho-machi, Tokushima 770-8505, Japan. takiguti@ph2.tokushima-u.ac.jp
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Takiguchi
authors.forename: Rie
authors.initials: R
authors.lastname: Ishihara
authors.forename: Mayumi
authors.initials: M
authors.lastname: Torii
authors.forename: Rinya
authors.initials: R
authors.lastname: Kato
authors.forename: Susumu
authors.initials: S
authors.lastname: Kamihara
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Uematsu
mesh_terms: D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000378:metabolism* / Q000493:pharmacokinetics; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005424:Flecainide / Q000378:metabolism* / Q000493:pharmacokinetics; D006197:Hair / Q000737:chemistry*; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D000889:Anti-Arrhythmia Agents; D005424:Flecainide