SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

M29
CODEINE AND METABOLITE DISPOSITION IN HUMAN SWEAT FOLLOWING
CONTROLLED ORAL CODEINE ADMINISTRATION
Eugene W. Schwilke 1 *, Sherri L. Kacinkol, Allan J. Barnesl, Jonathan M. Oyler2, Edward 1. Cone 3 , Eric T.
Moolchan l , and Marilyn A. Huestis l : IChemistry and Drug Metabolism Section, Intramural Research
Program, NIDA, NIH, Baltimore, MD, 2Department of the Army, US Army Research, Development and
Engineering Command, Aberdeen Proving Ground, MD, 3ConeChem Research, LLC., Severna Park, MD
Analysis of codeine is included in drug treatment, military, criminal justice and workplace programs
because of its abuse potential and performance impairing effects. Interest in monitoring drug exposure with
human sweat, as an alternative biological specimen is increasing, as sweat collections are convenient, less
invasive and difficult to adulterate. Our objective for this study was to determine the excretion profile of
codeine and metabolites into human sweat using the PharmChek Sweat Patch. Volunteers with a history
of opiate use (n=9) provided informed consent to participate in this IRB-approved study and resided on the
closed clinical research ward for 12 weeks. Low (60mg/70kg) and high (l20mg/70kg) doses of codeine
sulphate were administered three times a week, four weeks apart. Codeine, norcodeine, morphine,
normorphine, and 6-monoacetylmorphine were isolated by SPE and GCIEI-MS. The limit of quantitation
(LOQ) for codeine and morphine were 2.5 ng/patch, and 5 ng/patch for metabolites.
We present data from patches representing four categories of sweat collection. First, weekly sweat patches
were collected from the time of entry onto the secure ward until the time of first codeine administration,
reflecting excretion of previously self-administered opiates. No patch was positive for 6-acetylmorphine,
codeine, morphine or metabolites at the methods' LOQs.
Second, weekly sweat patches also were applied prior to and removed 7 days after dosing for 5 of 9 and 3
of 6 participants for the low and high doses, respectively. 80% of the low and 100% of the high dose
weekly patches were positive for codeine, but negative for metabolites. The mean codeine concentration for
these patches was 65 ng/patch (median 27, SD 92, range 16-225) for the low dose and 82 ng/patch (median
84, SD 15, range 67-96) for the high dose.
Third, other sweat patches were worn for between 1 to 15 hours during the first 48 hours after dosing. Of
139 patches worn during the first 48 hours following the first codeine administration, only 11 (8%)
contained codeine levels greater than our LOQ. Codeine was the only analyte detected and could be found
as early as 1 hour after dosing. A total of7 patches (8%) were positive for codeine following the low dose,
and 4 patches (8%) following the high dose. The mean codeine concentration (data from 3 of9 subjects) in
sweat was 43 ng/patch (median 28, SD 50, range 5 - 153) for the low dose and 12 ng/patch (median 11.0,
SD 9.0, range 3-24, data from 3 of 6 subjects) for the high dose. Codeine was detected in sweat patches for
up to 26 h after administration; patches applied after 26 hours and worn for up to 15 hours were below the
LOQ.
Fourth, weekly patches also were applied to 4 of 9 participants two weeks after the last codeine dose. All
of the patches also were negative for codeine and metabolites.
Sweat has recently been proposed by the Substance Abuse and Mental Health Services Administration
(SAMHSA) for federally-mandated workplace drug testing. A confirmation cutoff of 25 ng/patch has been
proposed for patches worn 7 to 14 days. Two patches for one subject and I patch for another collected
within the first 48 hours following dosing, would be positive using these criteria. In comparison, 6 of 8
patches worn for 7 days during the dosing period would be positive under the new SAMHSA guidelines.
Sweat provides an adequate matrix for detection of opioid use. There was large intra- and inter-subject
variability. No correlation of codeine concentration with dose was found for the doses investigated.
Patches worn for 1 week were more likely to contain codeine above the LOQ than patches worn for 1 to 15
hours.
Keywords: Sweat, Codeine, GCMS
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