Opioid disposition in human sweat after controlled oral codeine administration.
BACKGROUND
Characterization of opioid excretion in sweat is important for accurate interpretation of sweat tests in drug treatment, criminal justice, and workplace drug testing programs.


METHODS
Participants (n=20) received placebo, 3 low (60 mg/70 kg) or 3 high (120 mg/70 kg) codeine sulfate doses (used as a model for opioid excretion) within 1 week. Codeine and metabolites in sweat were collected with PharmChek Sweat Patches; hourly patches were applied for 1 to 15 h (n=775) and weekly patches for 7 days (n=118). Patches were analyzed by solid-phase extraction and gas chromatography-mass spectrometry for codeine, norcodeine, morphine, normorphine, and 6-acetylmorphine. Limits of quantification were 2.5 ng/patch (codeine and morphine) and 5 ng/patch (other analytes).


RESULTS
Codeine was the only analyte identified in 12.6% of hourly patches and 83.3% of weekly sweat patches worn during dosing. Weekly patch concentrations (SD) were 38.6 (59.9) ng/patch [median (range), 15.9 (0-225.1) ng/patch] for low and 34.1 (32.7) ng/patch [24.0 (0-96.2) ng/patch] for high codeine doses. Codeine detected 1 week after dosing was 4.6 (5.3) ng/patch [median (range), 4.0 (0-17.1) ng/patch; n=11] after low and 7.7 (7.1) ng/patch [6.9 (0-20.5) ng/patch; n=10] after high doses. In total, 2.6% of hourly, 38.5% of low-dose, and 45.5% of high-dose weekly patches contained codeine at the proposed Substance Abuse and Mental Health Services Administration cutoff.


CONCLUSIONS
Codeine was the only analyte detected, at highly variable concentrations, up to 2 weeks after dosing. These results are consistent, considering the complex processes of codeine deposition in sweat. Sweat testing is a useful alternative technique for qualitative monitoring of opioid use.
Schwilke
Eugene W
EW
Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA.
Barnes
Allan J
AJ
Kacinko
Sherri L
SL
Cone
Edward J
EJ
Moolchan
Eric T
ET
Huestis
Marilyn A
MA
D000284:Administration, Oral; D000328:Adult; D003061:Codeine / Q000032:analysis* / Q000493:pharmacokinetics; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D009294:Narcotics / Q000032:analysis* / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D015813:Substance Abuse Detection / Q000379:methods*; D013542:Sweat / Q000737:chemistry* / Q000378:metabolism; D013997:Time Factors
D009294:Narcotics; D003061:Codeine