Measurement of flecainide in hair as an index of drug exposure

✍ Scribed by Yoshiharu Takiguchi; Rie Ishihara; Rinya Kato; Susumu Kamihara; Masayuki Yokota; Toshihiko Uematsu

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 114 KB
• Volume: 90
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.1138

✦ Synopsis

We report a method for measuring the concentration of ¯ecainide in hair. An animal study, in which ¯ecainide (1, 5, and 10 mg/kg/day) was orally administered for 1, 2, and 3 weeks to pigmented rats, showed that ¯ecainide concentration in rat hairs newly regrown after administration signi®cantly correlated with both the daily dose and the dosing period. The part of hair containing ¯ecainide continued to grow upward, retaining the drug within the hair structure that had been formed at the time of drug exposure. Flecainide was also determined in human scalp hairs collected from patients treated with ¯ecainide. The drug content of white hairs was much less than that black hairs collected from the same rats and subjects, suggesting the determinant effect of hair pigment on ¯ecainide accumulation in hair. These ®ndings suggest that the analysis of ¯ecainide in hair may be useful for assessing exposure to drug qualitatively.