title: Incorporation of isotopically labeled cocaine into human hair: race as a factor.
abstract: In order to evaluate race as a possible factor affecting the incorporation of drugs into human hair, 2 mg/kg deuterium-labeled cocaine (cocaine-d5) was administered intranasally to nine male non-Caucasian volunteers under controlled laboratory conditions. Sequential blood samples were collected for up to three days, and scalp hair samples were collected at 24 and 72 h after dosing and at monthly intervals for up to 12 months. The samples were then analyzed by gas chromatography-mass spectrometry for cocaine-d5 and benzoylegonine-d5 (BZE-d5). The amounts of cocaine-d5 found in the hair of these non-Caucasian subjects were compared with the amounts of cocaine-d5 found in the hair of Caucasian subjects who received the same cocaine dose under identical conditions as part of a study we reported previously. The non-Caucasians in the present study had approximately 2.7 times more cocaine-d5 in their hair than the Caucasian subjects in the earlier study. In five of the non-Caucasian subjects, cocaine-d5 could be detected in hair within 24 h after dosing. Curiously, we were unable to detect any cocaine-d5 in one of the non-Caucasian subject's hair at any time after dosing even though cocaine-d5 was in plasma at the expected levels. The results from these studies suggest there may be a racial bias in the incorporation of cocaine into human hair; however, the data are not conclusive because of the relatively small sample size.
authors.affiliation: Department of Medical Pharmacology and Toxicology, School of Medicine, University of California, Davis 95616 USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Henderson
authors.forename: M R
authors.initials: MR
authors.lastname: Harkey
authors.forename: C
authors.initials: C
authors.lastname: Zhou
authors.forename: R T
authors.initials: RT
authors.lastname: Jones
authors.forename: P
authors.initials: P
authors.lastname: Jacob
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D044383:Black People / Q000235:genetics; D003042:Cocaine / Q000008:administration & dosage / Q000493:pharmacokinetics*; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry; D006197:Hair / Q000378:metabolism*; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D015813:Substance Abuse Detection; D019966:Substance-Related Disorders / Q000235:genetics* / Q000378:metabolism; D044465:White People / Q000235:genetics
chemical_list: D003903:Deuterium; D003042:Cocaine