Codeine disposition in human hair after single and multiple doses.
OBJECTIVE
We studied the dose-proportion and time-course relationships for the incorporation of codeine into human hair after the administration of three different groups.


METHODS
Male volunteers, with dark hair, were given oral codeine either as a single dose of 60 mg (n = 7) or 120 mg (n = 12) or as multiple doses of 30 mg 3 times daily for 5 days (n = 7) (450 mg total dose).


METHODS
Blood and urine were collected for various times for up to 72 h after dosing. Scalp hair was collected initially by plucking (up to 4 weeks) and later by cutting for up to 10 weeks. Plasma, urine, proximal 1 cm of hair and distal hair were each analyzed for codeine and its metabolites by positive-ion chemical ionization ion trap gas chromatography/mass spectrometry.


RESULTS
Codeine was detected in the proximal 1 cm of hair within 30 min of an oral 120-mg dose. Codeine was not detected in the distal hair segment until 3 weeks after receiving a dose of codeine. Codeine was detected in distal hair segments for at least 10 weeks at 30 pg mg-1 hair following a single 120 mg codeine dose and at 90 pg mg-1 hair following 30 mg codeine 3 times a day for 5 days. Morphine or the glucuronides of codeine or morphine were not detected in the hair specimens of these subjects.


CONCLUSIONS
Codeine is rapidly distributed into the germanitive elements of hair in a dose-proportional manner. A portion of the codeine remains bound as the hair grows and can be detected in distal hair for up to 10 weeks after a single dose.
Rollins
D E
DE
Department of Pharmacology and Toxicology, University of Utah Health Sciences Centre, Salt Lake City, USA.
Wilkins
D G
DG
Krueger
G G
GG
D000284:Administration, Oral; D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000378:metabolism* / Q000652:urine; D003061:Codeine / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000378:metabolism* / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D005965:Glucuronates / Q000097:blood / Q000652:urine; D006197:Hair / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008297:Male; D009020:Morphine / Q000097:blood / Q000652:urine
D000701:Analgesics, Opioid; D005965:Glucuronates; D009020:Morphine; D003061:Codeine