Excretion of methamphetamine and amphetamine in human sweat following controlled oral methamphetamine administration.
BACKGROUND
Understanding methamphetamine (MAMP) and amphetamine (AMP) excretion in sweat is important for interpreting sweat and hair testing results in judicial, workplace, and drug treatment settings.


METHODS
Participants (n = 8) received 4 10-mg (low) oral doses of sustained-release S-(+)-MAMP HCl (d-MAMP HCl) within 1 week in a double-blind, institutional review board-approved study. Five participants also received 4 20-mg (high) doses 3 weeks later. PharmChek sweat patches (n = 682) were worn for periods of 2 h to 1 week during and up to 3 weeks after dosing. The mass of MAMP and AMP in each patch was measured by GC-MS, with a limit of quantification of 2.5 ng/patch.


RESULTS
MAMP was measurable in sweat within 2 h of dosing. After low and high doses, 92.9% and 62.5% of weekly sweat patches were positive, with a median (range) MAMP of 63.0 (16.8-175) and 307 (199-607) ng MAMP/patch, respectively; AMP values were 15.5 (6.5-40.5) and 53.8 (34.0-83.4) ng AMP/patch. Patches applied 2 weeks after the drug administration week had no measurable MAMP following the low doses, and only 1 positive result following the high doses. Using criteria proposed by the Substance Abuse Mental Health Services Administration, 85.7% (low) and 62.5% (high) weekly sweat patches from the dosing week were positive for MAMP, and all patches applied after the dosing week were negative.


CONCLUSIONS
These data characterize the excretion of MAMP and AMP after controlled MAMP administration and provide a framework for interpretation of MAMP sweat test results in clinical and forensic settings.
Barnes
Allan J
AJ
Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 5500 Nathan Shock Drive, Baltimore, MD 21224, USA.
Smith
Michael L
ML
Kacinko
Sherri L
SL
Schwilke
Eugene W
EW
Cone
Edward J
EJ
Moolchan
Eric T
ET
Huestis
Marilyn A
MA
D000284:Administration, Oral; D000328:Adult; D000661:Amphetamine / Q000032:analysis*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000032:analysis; D015813:Substance Abuse Detection / Q000379:methods*; D013542:Sweat / Q000737:chemistry*
D003692:Delayed-Action Preparations; D008694:Methamphetamine; D000661:Amphetamine