title: Opioid disposition in human sweat after controlled oral codeine administration.
abstract: 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.
authors.affiliation: Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, NIH, Baltimore, MD 21224, USA.
authors.forename: Eugene W
authors.initials: EW
authors.lastname: Schwilke
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Barnes
authors.forename: Sherri L
authors.initials: SL
authors.lastname: Kacinko
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Cone
authors.forename: Eric T
authors.initials: ET
authors.lastname: Moolchan
authors.forename: Marilyn A
authors.initials: MA
authors.lastname: Huestis
mesh_terms: 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
chemical_list: D009294:Narcotics; D003061:Codeine