Future DUI Arrests May Be Justified by Obtaining
a Sweat Sampling
William C. Head, Attorney
at Law
Partner with Head, Thomas, Webb & Willis, LLC
Atlanta, Georgia, USA
The never-ending quest to detect and arrest
impaired drivers has led to new efforts to estimate both alcohol
quantities as well as certain contraband drugs in drivers
who might be stopped at roadside sobriety checkpoints. Science
has advanced tremendously since the first crude breath analysis
device was intorduced in America in the 1930's. Once reliability
has been improved, expect to have police officers request
a "sweat sample" from your forehead, to determine
whether you will be allowed to proceed to your chosen destination.
Dr. Robert Forrest, a government physician
located in England, has complied the following summary of
preliminary studies regarding "sweat" sampling.
The research seems destined to result in new devices and methods
for identifying and charging DUI-DWI drivers.
Drugs
in Sweat.
N.
Samyn, G. De Boeck and A. G. Verstraete (2002). "The use of
oral fluid and sweat wipes for the detection of drugs of abuse
in drivers." Journal of Forensic Sciences 47(6):
1380-7.
Blood, urine, oral fluid (by spitting or with a Salivette),
and sweat samples (by wiping the forehead with a fleece moistened
with isopropanol) were obtained from 180 drivers who failed
the field sobriety tests at police roadblocks. With quantitative
GC-MS, the positive predictive value of oral fluid was 98,
92, and 90% for amphetamines, cocaine, and cannabis respectively.
The prevalence of opiate positives was low. The proposed SAMHSA
cut-off values for oral fluid testing at the workplace, proved
their usefulness in this study. The positive predictive value
of sweat wipe analysis with GC-MS was over 90% for cocaine
and amphetamines and 80% for cannabis. The accuracy of Drugwipe
was assessed by comparing the electronic read-out values obtained
on-site after wiping the tongue and the forehead, with the
corresponding GC-MS results in plasma, oral fluid, and sweat.
The accuracy was always less than 90% except for the amphetamine-group
in sweat.
O.
Y. Al-Dirbashi, K. Ikeda, M. Takahashi, N. Kuroda, S. Ikeda
and K. Nakashima (2001). "Drugs of abuse in a non-conventional
sample; detection of methamphetamine and its main metabolite,
amphetamine in abusers' clothes by HPLC with UV and fluorescence
detection." Biomedical Chrmatography 15(7):
457-63.
In this paper, we report the detection of methamphetamine
and its major metabolite, amphetamine, in garments belong
to known-abusers. These compounds were extracted from the
textile using a mixture of chloroform:propan-2-ol (3:1, v/v),
derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl) benzoyl
chloride and separated using a reversed-phase high-performance
liquid chromatography. The derivatives were detected by measuring
either fluorescence at 440 nm or absorbance at 330 nm. By
using 1-methyl-3-phenyl propylamine as an internal standard,
calibration curves of spiked textile samples were linear over
a wide range with correlation coefficients of 0.997 or better.
Detection limits at a signal-to-noise ratio of 3 were less
than or equal to 37.3 and 0.4 pg on column for the high-performance
liquid chromatography-ultraviolet and -fluorescence detection
methods, respectively. Intra- and inter-day variations at
high and low concentrations (n > or = 3) were < or =12.7%.
The developed methods were successfully applied to the determination
of methamphetamine and amphetamine in clothes samples belong
to abusers. Copyright 2001 John Wiley & Sons, Ltd.
D.
J. Crouch, R. F. Cook, J. V. Trudeau, D. C. Dove, J. J. Robinson,
H. L. Webster and A. A. Fatah (2001). "The detection of drugs
of abuse in liquid perspiration." Journal of Analytical
Toxicology 25(7): 625-7.
D.
E. Moody and M. L. Cheever (2001). "Evaluation of immunoassays
for semiquantitative detection of cocaine and metabolites
or heroin and metabolites in extracts of sweat patches." Journal
of Analytical Toxicology 25(3): 190-7.
Two types of immunoassays, radioimmunoassay (RIA) and microplate
enzyme immunoassay (EIA), were compared for their ability
to detect and quantitate cocaine and metabolites or heroin
and metabolites in extracts of sweat patches. Experiments
used sweat patches that had been fortified with cocaine, benzoylecgonine
(BE), and ecgonine methyl ester (EME) or 6-acetylmorphine
(6-AM), heroin, and morphine. Assays were first evaluated
for sensitivity in detection of the analyte(s) known to be
excreted in sweat (cocaine >> BE and EME; 6-AM >
heroin > morphine). The cocaine metabolite RIA had cross-reactivity
for cocaine > BE > EME, and the cocaine metabolite EIA
had cross-reactivity for BE > cocaine >> EME. The
RIA, having greater sensitivity for COC, was studied further.
Optimal linearity was 4 to 200 ng/patch, and quantitation
within these limits at 4, 75, and 150 ng/patch had intrarun
%CVs within 7.8% and percent targets within 15% and inter-run
%CVs within 13.5% and % targets within 13%. The opiate RIA
had cross-reactivities for morphine >> 6-AM and heroin.
The opiate EIA had cross-reactivities for 6-AM and heroin
of 42 and 28% relative to morphine, respectively. The EIA,
having greater sensitivity for 6-AM and heroin, was studied
further. The limits of detection ranged from 1.7 to 24.7 ng/patch,
and the lower limits of quantitation ranged from 7.3 ng/patch
to beyond the linear range. The assay, however, had consistently
good precision at 4 and 5 ng/patch, and optimal linearity
was established from 4 to 100 ng/patch. With controls at 5,
25, and 90 ng/patch, both intrarun and inter-run precision
were acceptable. Quantitation was accurate at 5 and 25 ng/patch,
but the 90 ng/patch controls were consistently < 70% of
target. Because our studies focused on the assays that had
greater sensitivity for the analytes excreted in sweat, we
did not fully evaluate the cocaine metabolite EIA or the RIA
opiate screen and therefore cannot make any comment on the
usefulness of these assays for detecting analytes in extracts
of sweat patches beyond predicting that they will have less
sensitivity. Both the cocaine metabolite RIA and opiate EIA
had the ability to detect analytes known to be extracted from
sweat patches.
R.
Pacifici, M. Farre, S. Pichini, J. Ortuno, P. N. Roset, P.
Zuccaro, J. Segura and R. de la Torre (2001). "Sweat testing
of MDMA with the Drugwipe analytical device: a controlled
study with two volunteers." Journal of Analytical Toxicology
25(2): 144-6.
Rapid on-site tests for the analysis of drugs of abuse in
unconventional specimens (e.g., sweat) have recently been
developed. Two healthy volunteers familiar with the effects
of methylenedioxymethamphetamine (MDMA) were given 100 mg
of the drug as a single oral dose. MDMA and its main metabolite
4-hydroxy-3-methoxymethamphetamine (HMMA) were determined
in plasma and urine by gas chromatography-mass spectrometry
(GC-MS). MDMA was also investigated in sweat with the Drugwipe
(an immunochemical strip test). Subjects' armpits were swabbed
for 10 s at 0 time (predose) and at 2, 6, 8, 12, and 24 h
after MDMA administration. MDMA consumption could be detected
using Drugwipe at 2 h and for as long as 12 h after drug administration.
However, in one of the volunteers, a faint color change appeared
at 0 time, when plasma and urine tested negative for MDMA
and did not disappear even 48 h later. Plasma concentrations
of MDMA and HMMA measured by GC-MS peaked at 2-4 h, and values
greater than 20 ng/mL for MDMA and of 40 ng/mL for HMMA were
still detected at 24 h. Urine tested positive by GC-MS for
MDMA and HMMA in the 48-h collection period. These findings
preliminarily support sweat testing with Drugwipe for monitoring
MDMA use.
Y.
H. Caplan and B. A. Goldberger (2001). "Alternative specimens
for workplace drug testing." Journal of Analytical Toxicology
25(5): 396-9.
Recent advances in analytical techniques have enabled the
detection of drugs and drug metabolites in alternative biological
specimens for the purposes of workplace testing. A wide variety
of specimens are available, each providing valuable information
concerning prior or current drug use. The present focus is
on oral fluid (saliva), hair, and sweat. An extensive evaluation
by the Division of Workplace Programs of the Department of
Health and Human Services is underway to determine the utility
of these specimens in federally regulated programs. In future
years, the testing of alternative specimens will expand our
ability to understand the patterns of drug use and will become
routine in all areas of forensic toxicology. [References:
6]
D.
A. Kidwell and F. P. Smith (2001). "Susceptibility of PharmChek
drugs of abuse patch to environmental contamination." Forensic
Science International. 116(2-3): 89-106.
The key component of the PharmChek sweat patch, the membrane,
has been tested for the passage of externally applied materials.
Drugs in the uncharged state rapidly penetrated the membrane
but charged species were greatly slowed. In basic media, detectable
concentrations of cocaine, methamphetamine, and heroin were
observed at the earliest collection time (ca. 30 s), after
drugs were placed on the outside of the membrane. Drug concentrations
increased over the 2 h time course, when amounts detected
(1710 ng cocaine, 1060 ng methamphetamine, 550 ng heroin per
pad at 2 h) represented 5-17% of the drug deposited on the
surface of the sweat patch.Drugs externally applied to human
skin were shown to bind readily. Drugs deposited on the skin
of drug-free volunteers several days prior to application
of the sweat patch were not completely removed by normal hygiene
or the cleaning procedures recommended before application
of the sweat patch. Even 6 days of normal hygiene did not
remove all drugs from externally contaminated skin and positive
sweat patches resulted. A mechanism for passage of drugs through
the sweat patch membrane, a mechanism for retention of drugs
on skin, and a redesign of the sweat patch and modification
of its use to reduce external contamination are proposed.
Appropriate care should be taken in the interpretation of
positive results from a sweat patch test until more research
is conducted.
V.
Spiehler (2000 Jan 10). "Hair analysis by immunological methods
from the beginning to 2000." Forensic Science International.
107(1-3): 249-59.
Immunoassays for hair testing must satisfy three requirements:
(1) They must have cross-reactivity with parent drug and lipophilic
metabolites actually found in hair (2) they must not experience
interference from the dissolved hair matrix and (3) they must
be titered for cutoffs appropriate to the drug concentrations
found in hair. Because the analytes found in hair after drug
use are generally the parent drug or its lipophilic metabolites,
immunoassays developed and intended for urine testing are
not suitable for hair. Immunoassays whose antibodies are bound
to a solid support, such as coated-tube radioimmunoassay or
coated-plate ELISA tests, experience less matrix interference
than those which use other means of separation of bound and
free fractions. Homogenous assays are not suitable for hair
testing because the hair matrix frequently interferes in the
detection of the signal. Historically radioimmunoassays for
drugs of abuse were first used for detecting drugs in hair.
Currently ELISAs and coated-plate 96 well microplate EIAs
are employed for screening hair digests or extracts for drugs.
The optimum cutoffs for immunoassays for drugs in hair should
be chosen based on the analyte concentration which produces
the fewest false positive or false negative results when applied
to tests of hair from known users and non-users of drugs.
A hair immunoassay test at these cutoffs should have a sensitivity
and specificity of better than 90%. The predictive value of
the test will depend on the prevalence of drug use in the
tested population. Cutoffs or decision thresholds for immunoassays
used for screening for drugs should not be at the limit of
detection of the assay because that produces a very large
incidence of false positives. Because immunoassays are ligand-binding
assays, they have a short range of linearity with low precision
at both ends of the range. In the future, immunoassays will
continue to be used for screening hair and other matrices
for drugs of abuse because they provide rapid, inexpensive
automated procedures for separating negative specimens from
those which are suspected of containing drugs. For forensic
purposes, all positive results must be confirmed by an independent
analysis using a procedure based on a different property of
the analyte. An immunoassay test should not be confirmed by
a second immunoassay test but by a chromatographic test performed
on a different dissolved or extracted aliquot of the original
specimen. [References: 24]
M.
A. Huestis, E. J. Cone, C. J. Wong, A. Umbricht and K. L.
Preston (2000). "Monitoring opiate use in substance abuse
treatment patients with sweat and urine drug testing." Journal
of Analytical Toxicology 24(7): 509-21.
Although urine testing remains the standard for drug use monitoring,
sweat testing for drugs of abuse is increasing, especially
in criminal justice programs. One reason for this increase
is sweat testing may widen the detection window compared to
urine testing. Drug metabolites are rapidly excreted in urine
limiting the window of detection of a single use to a few
days. In contrast, sweat collection devices can be worn for
longer periods of time. This study was designed to compare
the efficacy of sweat testing versus urine testing for detecting
drug use. Paired sweat patches that were applied and removed
weekly on Tuesdays were compared to 3-5 consecutive urine
specimens collected Mondays, Wednesdays, and Fridays (355
matched sweat and urine specimen sets) from 44 patients in
a methadone-maintenance outpatient treatment program. All
patches (N = 925) were extracted in 2.5 mL of solvent and
analyzed by ELISA immunoassay for opiates (cutoff concentration
10 ng/mL). A subset (N = 389) of patches was analyzed by gas
chromatography-mass spectrometry (GC-MS). Urine specimens
(N = 1886) were subjected to qualitative analysis by EMIT
(cutoff 300 ng/mL). Results were evaluated to (1) determine
the identity and relative amounts of opiates in sweat; (2)
assess replicability in duplicate patches; (3) compare ELISA
and GC-MS results for opiates in sweat; and (4) compare the
detection of opiate use by sweat and urine testing. Opiates
were detected in 38.5% of the sweat patches with the ELISA
screen. GC-MS analysis confirmed 83.4% of the screen-positive
sweat patches for heroin, 6-acetylmorphine, morphine, and/or
codeine (cutoff concentration 5 ng/mL) and 90.2% of the screen-negative
patches. The sensitivity, specificity, and efficiency of ELISA
opiate results as compared to GC-MS results in sweat were
96.7%, 72.2%, and 89.5%, respectively. Heroin and/or 6-acetylmorphine
were detected in 78.1% of the GC-MS-positive sweat patches.
Median concentrations of heroin, 6-acetylmorphine, morphine,
and codeine in the positive sweat samples were 10.5, 13.6,
15.9, and 13.0 ng/mL, respectively. Agreement in paired sweat
patch test results was 90.6% by ELISA analysis. For the purposes
of this comparison of ELISA sweat patch to EMIT urine screening
for opiates, the more commonly used urine test was considered
to be the reference method. The sensitivity, specificity,
and efficiency of sweat patch results to urine results for
opiates were 68.6%, 86.1%, and 78.6%, respectively. There
were 13.5% false-negative and 7.9% false-positive sweat results
as compared to urine tests. Analysis of sweat patches provides
an alternate method for objectively monitoring drug use and
provides an advantage over urine drug testing by extending
drug detection times to one week or longer. In addition, identification
of heroin and/or 6-acetylmorphine in sweat patches confirmed
the use of heroin in 78.1% of the positive cases and differentiated
illicit heroin use from possible ingestion of codeine or opiate-containing
foods. However, the percentage of false-negative results,
at least in this treatment population, indicates that weekly
sweat testing may be less sensitive than thrice weekly urine
testing in detecting opiate use.
L.
Rivier (2000). "Techniques for analytical testing of unconventional
samples." Best Practice & Research Clinical Endocrinology
& Metabolism. 14(1): 147-65.
Forensic scientists have long detected the presence of drugs
and their metabolites in biological materials using body fluids
such as urine, blood and/or other biological liquids or tissues.
For doping analysis, only urine has so far been collected.
In recent years, remarkable advances in sensitive analytical
techniques have encouraged the analysis of drugs in unconventional
biological samples such as hair, saliva and sweat. These samples
are easily collected, although drug levels are often lower
than the corresponding levels in urine or blood. This chapter
reviews recent studies in the detection of doping agents in
hair, saliva and sweat. Sampling, analytical procedures and
interpretation of the results are discussed in comparison
with those obtained from urine and blood samples. [References:
76]
N.
Samyn and C. van Haeren (2000). "On-site testing of saliva
and sweat with Drugwipe and determination of concentrations
of drugs of abuse in saliva, plasma and urine of suspected
users." International Journal of Legal Medicine. 113(3):
150-4.
Potential drug users participated voluntarily in a Belgian
study on the usefulness of the non-instrumental immunoassay
Drugwipe (Securetec, Germany) for the screening of cocaine,
opiates, amphetamine and cannabinoids in saliva and sweat.
If one of the screening assays (urine, oral fluid, sweat)
showed a positive result, blood and saliva were collected.
The on-site Drugwipe results were correlated with the Drugwipe
results for saliva in the laboratory and with the GC/MS results
of the corresponding saliva, plasma and urine samples and
pharmacological effects at the time of sampling. The Drugwipe
assay proved to be sufficiently sensitive for the detection
of recent cocaine (n = 6) and amphetamine (n = 15) abuse,
whether the device was wiped on the tongue or on the surface
of the body, or when a saliva sample was applied to the wiping
part. In five of the six potential cocaine users, the saliva
concentrations of cocaine exceeded 1,000 ng/ml. In the amphetamine
group, the saliva concentrations of amphetamine, MDMA or both
were high (> 1,000 ng/ml) in 13 subjects. For cocaine and
amphetamine, the positive scores for Drugwipe matched the
GC/MS results for the three body fluids. Recent heroin abuse
(n = 5) could be demonstrated to some extent with Drugwipe
on samples from the tongue but only the two subjects with
the highest saliva concentrations of MAM (> 500 ng/ml)
and morphine (> 500 ng/ml) were positive. If the legal
cut-off value for driving under the influence of opiates in
Belgium (20 ng/ml of free morphine in plasma) was taken into
account, only three subjects would have been legally positive.
For cannabinoids (n = 15), false negatives and even some false
positives were observed. Saliva can be considered as a useful
analytical matrix for the detection of drugs of abuse after
recent abuse when analysed with GC/MS.
J.
A. Levisky, D. L. Bowerman, W. W. Jenkins and S. B. Karch
(2000). "Drug deposition in adipose tissue and skin: evidence
for an alternative source of positive sweat patch tests."
Forensic Science International. 110(1): 35-46.
In a series of licit and illicit drug-related deaths, qualitative
and quantitative analyses on extracts of adipose tissue and
skin were performed by GC/MS. In all cases, the adipose tissue
was found to contain drugs at concentrations lower than, approximately
equal to, or even greater than the concentrations of the same
analytes found in the blood, which may reflect a consequence
of long-term chronic exposure, or acute intoxication, or some
combination of both. Approximately one cubic inch of skin
with adipose tissue was removed from the mid to lower abdominal
region adjacent to the midline incision during autopsy. The
drugs were recovered from the specimens following incubation
and alkaline, acidic, and alkaline chloroform back extraction
of one to three grams of tissue. Deuterated analogs of the
analytes were added to the matrix at the beginning of the
incubation period. Cocaine and free morphine (from heroin)
were readily identified in several cases. The presence of
these illicit drugs in adipose tissue raises significant forensic
questions, especially the use of 'sweat patches' to monitor
recent cocaine or heroin use in chronic drug users.
P.
Kintz, V. Cirimele and B. Ludes (2000). "Detection of cannabis
in oral fluid (saliva) and forehead wipes (sweat) from impaired
drivers." Journal of Analytical Toxicology 24(7):
557-61.
Saliva and sweat have been presented as two alternative matrices
for the establishment of drug abuse. The noninvasive collection
of a saliva or sweat sample, which is relatively easy to perform
and can be achieved under close supervision, is one of the
most important benefits in a driving-under-the-influence situation.
Moreover, the presence of certain analytes in saliva is a
better indication of recent use than when the drug is detected
in urine, so there is a higher probability that the subject
is experiencing pharmacological effects at the time of sampling.
We developed an original procedure using gas chromatography-mass
spectrometry to test for delta9-tetrahydrocannabinol (THC),
the psychoactive ingredient of cannabis, in oral fluid and
forehead wipes, collected with Sarstedt Salivettes and cosmetic
pads, respectively. Blood, urine, oral fluid, and forehead
wipes were simultaneously collected from 198 injured drivers
admitted to an Emergency Hospital in Strasbourg, France. Of
the 22 subjects positive for 11-nor-9-carboxy-THC (THCCOOH)
in urine, 14 and 16 were positive for THC in oral fluid (1
to 103 ng/Salivette) and forehead wipe (4 to 152 ng/pad),
respectively. 11-Hydroxy-THC and THCCOOH were not detected
in these body fluids. Two main limitations of saliva and sweat
are apparent: the amount of matrix collected is smaller when
compared to urine, and the levels of drugs are higher in urine
than in saliva and sweat. A current limitation in the use
of these specimens for roadside testing is the absence of
a suitable immunoassay that detects the parent compound in
sufficiently low concentrations.
D.
E. Moody (2000). "Units for sweat patch results.[comment]."
Journal of Analytical Toxicology 24(8):
733.
R.
E. Joseph, Jr., K. M. Hold, D. G. Wilkins, D. E. Rollins and
E. J. Cone (1999). "Drug testing with alternative matrices
II. Mechanisms of cocaine and codeine deposition in hair."
Journal of Analytical Toxicology. 23(6): 396-408.
A 10-week inpatient study was performed to evaluate cocaine,
codeine, and metabolite disposition in biological matrices
collected from volunteers. An initial report described drug
disposition in plasma, sebum, and stratum corneum collected
from five African-American males. This report focuses on drug
disposition in hair and sweat collected from the same five
subjects. Following a three-week washout period, three doses
of cocaine HCl (75 mg/70 kg, subcutaneous) and three doses
of codeine SO4 (60 mg/70 kg, oral) were administered on alternating
days in week 4 (low-dose week). The same dosing sequence was
repeated in week 8 with doubled doses (high-dose week). Hair
was collected by shaving the entire scalp once each week.
Hair from the anterior vertex was divided into two portions.
One portion was washed with isopropanol and phosphate buffer;
the other portion was not washed. Hair was enzymatically digested,
samples were centrifuged, and the supernatant was collected.
Sweat was collected periodically by placing PharmChek sweat
patches on the torso. Drugs were extracted from sweat patches
with methanol/0.2 M sodium acetate buffer (75:25, v/v). Supernatants
from hair digests, hair washes, and sweat patch extracts were
processed by solid-phase extraction followed by gas chromatography-mass
spectrometry analysis for cocaine, codeine, 6-acetylmorphine,
and metabolites. Cocaine and codeine were the primary analytes
identified in sweat patches and hair. Drugs were detected
in sweat within 8 h after dosing, and drug secretion primarily
occurred within 24 h after dosing. No clear relationship was
observed between dose and drug concentrations in sweat. Drug
incorporation into hair appeared to be dose-dependent. Drugs
were detected in hair within 1-3 days after the last drug
administration; peak drug concentrations generally occurred
in the following 1-2 weeks; thereafter, drug concentrations
decreased. Solvent washes removed 50-55% of cocaine and codeine
from hair collected 1-3 days after the last drug dose. These
data may reflect removal of drug that was deposited by sweat
shortly after dosing. Drug removed by washing hair collected
1-3 weeks after the last dose was minimal for cocaine but
variable for codeine. Drug in these specimens was likely transferred
from blood to germinative hair cells followed by emergence
of drug in growing hair. These findings suggest that drug
deposition in hair occurs by multiple mechanisms.
K.
L. Preston, M. A. Huestis, C. J. Wong, A. Umbricht, B. A.
Goldberger and E. J. Cone (1999). "Monitoring cocaine use
in substance-abuse-treatment patients by sweat and urine testing.[comment]."
Journal of Analytical Toxicology. 23(5): 313-22.
Sweat and urine specimens were collected from 44 methadone-maintenance
patients to evaluate the use of sweat testing to monitor cocaine
use. Paired sweat patches that were applied and removed weekly
(on Tuesdays) were compared with 3-5 consecutive urine specimens
collected Mondays, Wednesdays, and Fridays. All patches (N
= 930) were extracted in 2.5 mL of solvent and analyzed by
ELISA immunoassay (cutoff concentration 10 ng/mL); a subset
of patches (N = 591) was also analyzed by gas chromatography-mass
spectrometry (GC-MS) for cocaine, benzoylecgonine (BZE), and
ecgonine methyl ester (EME) (cutoff concentration 5 ng/mL).
Urine specimens were subjected to qualitative analysis by
EMIT (cutoff 300 ng/mL) and subsets were analyzed by TDx (semiquantitative,
LOD 30 ng/mL) and by GC-MS for cocaine (LOD 5 ng/mL). Results
were evaluated to (1) determine the relative amounts of cocaine
and its metabolites in sweat; (2) assess replicability in
duplicate patches; (3) compare ELISA and GC-MS results for
cocaine in sweat; and (4) compare the detection of cocaine
use by sweat and urine testing. Cocaine was detected by GC-MS
in 99% of ELISA-positive sweat patches; median concentrations
of cocaine, BZE, and EME were 378, 78.7, and 74 ng/mL, respectively.
Agreement in duplicate patches was approximately 90% by ELISA
analysis. The sensitivity, specificity, and efficiency of
sweat ELISA cocaine results as compared with sweat GC-MS results
were 93.6%, 91.3%, and 93.2%, respectively. The sensitivity,
specificity, and efficiency between ELISA sweat patch and
EMIT urine results were 97.6%, 60.5%, and 77.7%, respectively.
These results support the use of sweat patches for monitoring
cocaine use, though further evaluation is needed.
G.
Skopp and L. Potsch (1999). "Perspiration versus saliva--basic
aspects concerning their use in roadside drug testing." International
Journal of Legal Medicine. 112(4): 213-21.
Various aspects concerning the practical application and forensic
interpretation of data obtained by saliva drug testing and
drug monitoring from the skin surface are discussed. Basic
information on the composition of saliva and skin secretions
and their particular transport mechanisms, as far as known,
are given. For drugs of abuse secretion into saliva is suggested
to be by passive diffusion and to depend on lipid solubility,
pKa, plasma protein binding and on the pH of saliva. Drug
molecules from blood are considered to reach the skin surface
by various routes such as by sweat and sebum as well as by
inter- and/or transcellular diffusion. The role of the stratum
corneum as a temporary drug reservoir exceeding positive drug
findings in urine is outlined. Current data on opioids, cocaine
metabolites, cannabinoids and amphetamines detected in saliva
and on the skin surface are reviewed. Aspects of collection,
processing and analysis of the samples for implementation
in roadside testing are addressed. The requirement of test
sensitivity covering the broad concentration ranges and the
importance of test specificity bearing in mind that the parent
drug is the main analyte present in those specimens is stressed.
Theoretical and practical findings on frequently abused drugs
are discussed with regard to the possibilities and limitations
of drug monitoring from saliva and perspiration to support
a suspicion of actual or recent drug administration. [References:
74]
D.
A. Kidwell, J. C. Holland and S. Athanaselis (1998). "Testing
for drugs of abuse in saliva and sweat.[erratum appears in
J Chromatogr B Biomed Sci Appl 1999 Jan 22;721(2):333]." Journal
of Chromatography. B, Biomedical Sciences & Applications
713(1): 111-35.
The detection of marijuana, cocaine, opiates, amphetamines,
benzodiazepines, barbiturates, PCP, alcohol and nicotine in
saliva and sweat is reviewed, with emphasis on forensic applications.
The short window of detection and lower levels of drugs present
compared to levels found in urine limits the applications
of sweat and saliva screening for drug use determination.
However, these matrices may be applicable for use in driving
while intoxicated and surveying populations for illicit drug
use. Although not an illicit drug, the detection of ethanol
is reviewed because of its importance in driving under the
influence. Only with alcohol may saliva be used to estimate
blood levels and the degree of impairment because of the problems
with oral contamination and drug concentrations varying depending
upon how the saliva is obtained. The detection of nicotine
and cotinine (from smoking tobacco) is also covered because
of its use in life insurance screening and surveying for passive
exposure. [References: 217]
P.
Kintz, V. Cirimele and B. Ludes (1998). "Codeine testing in
sweat and saliva with the Drugwipe." International Journal
of Legal Medicine 111(2): 82-4.
With the growing interest in drug testing within different
sectors of society, there has become a need for drug assays
that can be performed immediately at the site of specimen
collection. Recently, Securetec (Ottobrunn, Germany) has introduced
the Drugwipe, a non instrument-based, on-site immunodiagnostic
assay for the detection of drugs on surfaces. Different tests
are available for opiates, cocaine and cannabis. To document
the applications of the Drugwipe "opiate" on human
biological fluids, 60 mg codeine phosphate were orally administered
to 6 subjects. First, sweat testing with the Drugwipe was
studied. The wiping section of the kit was used to swab the
forehead of the subjects for 10 s, at 1, 4, 9 and 24 h after
codeine administration. At the same time, for each period,
a sweat patch (Pharmchek, USA) was applied to the outer portion
of the upper arm. Codeine was then quantified in the patch
by GC/MS and the measured concentrations used as reference.
In all subjects except one the Drugwipe tested positive for
opiates, however with few false negative results. In the second
part of the study, results of the Drugwipe were compared with
those obtained by GC/MS for saliva. The tongue of the subjects
was carefully wiped over a period 24 h, and at the same time
a specimen of saliva collected. Although codeine could be
detected using the Drugwipe, numerous false negative results
were observed. Codeine tested positive by GC/MS but remained
negative using the Drugwipe in several cases. This can be
explained by a codeine concentration which was too low to
show positive with the Drugwipe, interfering substances may
be present in saliva or the sampling procedure is inadequate.
P.
Kintz, A. Tracqui, C. Marzullo, A. Darreye, F. Tremeau, P.
Greth and B. Ludes (1998). "Enantioselective analysis of methadone
in sweat as monitored by liquid chromatography/ion spray-mass
spectrometry." Therapeutic Drug Monitoring 20(1):
35-40.
In recent years, remarkable advances in sensitive analytical
techniques have enabled the analysis of drugs in unconventional
samples, such as sweat. In a study conducted during a methadone
maintenance program, PharmChek sweat patches were applied
to 20 subjects. The subjects were orally administered methadone
in 1 dosage/day, and doses ranged from 80 to 100 mg. The sweat
patch was applied 10 minutes before administration and removed
72 hours later just before a new administration of methadone.
The absorbent pad was stored at -20 degrees C until analysis
in plastic tubes. Methadone was extracted in 5 ml methanol
in presence of 200 ng of racemic methadone-d3, used as internal
standard. After a 30-minute agitation, the methanol solution
was evaporated to dryness. Enantioselective separation of
methadone was obtained using an alpha-1-acid glycoprotein
column (100 x 4 mm ID) and liquid chromatography/ion spray-mass
spectrometry. In all 20 specimens obtained from subjects under
racemic methadone treatment, R- (the active form) and S-enantiomers
of methadone were identified with the following concentrations:
26 to 1118 ng/patch for R-methadone and 28 to 1114 ng/patch
for S-methadone. The ratio between R- and S-methadone was
in the range of 0.72 to 2.66 and was higher than 1.00 in 15
samples. No correlation between the doses of methadone administered
and the concentrations of methadone in sweat was observed.
D.
S. Shearer, G. J. Baciewicz and T. C. Kwong (1998). "Drugs
of abuse testing in a psychiatric outpatient service." Clinics
in Laboratory Medicine 18(4): 713-26.
Drug testing of patients in a psychiatric outpatient service
is an effective way to identify patients who relapse into
renewed use of drugs of abuse and in monitoring the effectiveness
of ongoing medical and psychological therapy. Most of this
testing involves the analysis of urine specimens with immunoassays.
Hair testing affords an alternative specimen matrix that is
easy to obtain and not readily adulterated and offers the
advantage of a wider surveillance window. Hair analysis is
technically demanding, and the possibility of false-positives
caused by environmental contamination renders it a controversial
alternative. Sweat and saliva are potentially useful testing
matrices, but their usefulness in clinical practice must await
validation by additional clinical and laboratory experience.
The correct interpretation of drug test results is predicated
on knowing the performance characteristics of the analytical
method, route of administration, and pharmacokinetics of the
drug. All questionable positive results need confirmation
testing to verify true positivity. [References: 100]
P.
Kintz, R. Brenneisen, P. Bundeli and P. Mangin (1997). "Sweat
testing for heroin and metabolites in a heroin maintenance
program." Clinical Chemistry 43(5): 736-9.
Recent advances in sensitive analytical techniques have enabled
the analysis of drugs in unconventional biological materials
such as sweat. In a study conducted during a heroin maintenance
program, 14 subjects had sweat patches applied, then received
intravenously two or three doses of heroin hydrochloride ranging
from 80 to 1000 mg/day. The sweat patch was applied 10 min
before the first dosage and removed approximately 24 h later,
minutes before the next dosage. Absorbent pads were stored
at -20 degrees C in plastic tubes until analysis. The target
drugs were extracted in 5 mL of acetonitrile in the presence
of 100 ng each of heroin-d9, 6-acetylmorphine-d3, and morphine-d3.
After agitation for 30 min, the acetonitrile solution was
divided into two portions: 2 mL for heroin testing and the
remainder for testing for the other compounds. After evaporation,
the residue of the first portion was reconstituted in 35 microL
of acetonitrile; the second was derivatized by silylation
with 40 microL of N,O-bis(trimethylsilyl)trifluoroacetamide
containing 10 mL/L trimethylchlorosilane. Drugs were analyzed
by GC-MS in electron impact mode. Concentrations (nanograms
per patch) ranged from 2.1 to 96.3 for heroin, 0 to 24.6 for
6-acetylmorphine, and 0 to 11.2 morphine. Except in one case,
heroin was the major drug present in sweat, followed by 6-acetylmorphine
and morphine. We observed no correlation between the doses
of heroin administered and the concentrations of heroin measured
in sweat.
R.
Fogerson, D. Schoendorfer, J. Fay and V. Spiehler (1997).
"Qualitative detection of opiates in sweat by EIA and GC-MS.[comment]."
Journal of Analytical Toxicology 21(6): 451-8.
Sweat was collected with the PharmChek sweat patch, and drugs
were eluted from the collection pad of the patch. A solid-phase
enzyme immunoassay (EIA) using microtiter plates was modified
for the analysis of opiates in sweat. After opiate administration,
sweat contains primarily parent opiate (heroin, codeine) and
lipophilic metabolites (6-monoacetylmorphine [6-MAM]). The
immunoassay was determined to have a cross-reactivity with
codeine of 588%, with hydrocodone of 143%, with diacetylmorphine
of 28%, and with 6-MAM of 30% relative to 100% for the morphine
calibrators. The optimum cutoff concentration for this modified
assay was determined by receiver operator characteristic analysis
using 215 patches from 95 subjects to be 10 ng/mL morphine
equivalents. At this cutoff concentration the assay had a
diagnostic sensitivity of 86.9% and a diagnostic specificity
of 92.8% versus gas chromatography-mass spectrometry (GC-MS),
which was the reference method. The positive predictive value
at a prevalence of 50% was 86%. The intra-assay precision
at 10 ng/mL was 7.8%, and the interassay coefficient of variation
(CV) was 39%. Analysis of spiked patches around the cutoff
gave a percent positive threshold of approximately 50% between
10 and 15 ng/mL and a 95% confidence level for a positive
result by the EIA between 20 and 25 ng/mL. Eighteen possible
adulterants that could be injected into or under the patch
were studied. Two (tile cleaner and detergent) can cause false-positive
responses in the immunoassay. Two adulterants reduced response
to spiked drug (Visine eye drops and Ben Gay ointment), which
could cause a false-negative response. All results were confirmed
by GC-MS. The clinical sensitivity and specificity for detecting
drug use by analyzing sweat collected from human subjects
following known doses of codeine (0, 30, and 60 mg orally)
or heroin (20 mg intravenously) were 76 and 100%, respectively.
P.
Kintz, C. Sengler, V. Cirimele and P. Mangin (1997). "Evidence
of crack use by anhydroecgonine methylester identification."
Human & Experimental Toxicology 16(2): 123-7.
A method using gas chromatography coupled to mass spectrometry
for the determination of cocaine (COC) pyrolysis product,
anhydroecgonine methylester (AEME), in plasma, saliva, urine,
sweat and hair is described. The same procedure allows the
simultaneous determination of COC, benzoylecgonine (BZE),
ecgonine methylester (EME) and cocaethylene (CE). After suitable
sample preparation (desorption of the sweat patch, acid hydrolysis
of the hair) the target drugs were extracted using a 3-steps
liquid-liquid extraction (pH 8.4) in presence of deuterated
internal standards in chloroform-isopropanol-n-heptane (50
: 17 : 33, v/v). Derivatization was achieved using BSTFA+1%
TMCS. Ions for AEME monitoring were m/z 82, 166, 152 and 181.
Artifact formation from COC or EME of AEME during the injection
was less than 0.5%. AEME was never detected in blood sample
although the corresponding urine tested positive. Urine concentrations,
in about 90 positive AEME samples, were in the range 5 to
1477 ng/ml. In one case of crack overdose, AEME in sweat was
53 ng/patch with a COC concentration of 1231 ng/patch. AEME
in saliva ranged from 5 to 18 ng/ml in the same case. Finally,
AEME was identified in 32 hair specimens of crack abusers
including fetal hair, with concentrations in the range 0.20
to 21.56 ng/mg. These results suggest that AEME can be a useful
marker for the detection of COC smoking in clinical and forensic
cases.
D.
A. Kidwell, M. A. Blanco and F. P. Smith (1997). "Cocaine
detection in a university population by hair analysis and
skin swab testing." Forensic Science International
84(1-3): 75-86.
The ability to detect cocaine use/exposure by either hair
or sweat analysis was compared in a random population of adults
at a major US university. Sweat was obtained by wiping the
forehead with a cosmetic puff containing isopropanol. Using
cut-off levels for sweat of 2.2 ng cocaine/wipe and of hair
of 0.05 ng cocaine/mg hair, sweat detected two times more
cocaine use/exposure than did hair. Sweat analysis detected
a use rate of 12% compared to a 6% rate by hair analysis,
both greater than the 2% that would be expected in this population.
The high rate of detection was surprising and suggests that
use of, if not exposure to, cocaine is underreported. Controlled
experiments showed that cocaine could remain on the skin for
about 3 days after external exposure. At the current state
of knowledge, sweat appears to measure both use and exposure.
Nevertheless, sweat testing could be used in several scenarios
(such as roadside driving while intoxicated) where the case
of collection and testing of sweat could outweigh the passive
exposure considerations. Cocaine concentrations in skin swabs
> 15 ng/swab would appear to indicate recent use/exposure.
G.
Skopp, L. Potsch and M. R. Moeller (1997). "On cosmetically
treated hair--aspects and pitfalls of interpretation." Forensic
Science International 84(1-3): 43-52.
Popular hair cosmetic treatments like bleaching or permanent
waving were found to affect the stability of incorporated
drugs and to cause alterations of the fibers at an ultrastructural
level. This may result in a partial or complete loss of drug
substances, depending on the particular drug molecule and
on its concentration prior to the cosmetic treatment. Moreover,
from literature, there is some evidence that drug molecules
are not only incorporated into the growing fiber by passive
diffusion from blood into the matrix cells and melanocytes,
but that the substances enter the hair also via perspiration
such as sweat and sebum. Since permed and bleached hair shows
an enhanced sorption capacity, the risk of false positives
or an unusually high drug concentration in cosmetically treated
hair was under investigation. Virgin, permed, mildly as well
as severely bleached tresses were exposed to artificial sweat
or sebum containing cocaine, benzoylecgonine, 6-acetylmorphine,
morphine and codeine (500 ng/g). Except codeine, the concentrations
measured by GC/MS were very small and quite close to the detection
limit indicating a minor importance of drug uptake into hair
fiber from the endogenous-exogenous shunt via sebum or sweat.
From the results it is concluded that an increased risk of
false positive results in hair analysis on bleached and permanent
waved hair fibers does exist, but is not particularly severe.
V.
Spiehler, J. Fay, R. Fogerson, D. Schoendorfer and R. S. Niedbala
(1996). "Enzyme immunoassay validation for qualitative detection
of cocaine in sweat." Clinical Chemistry 42(1):
34-8.
A solid-phase enzyme immunoassay (EIA) involving microtiter
plates was modified for analysis of cocaine in sweat. Sweat
was collected with the PharmChek sweat patch and drugs were
eluted from the collection pad of the patch. The sweat contained
primarily parent cocaine. The assay was determined to have
cross-reactivity for cocaine of 102% relative to 100% for
the benzoylecgonine (BE) calibrators and for cocaethylene
of 148%. The optimum cutoff concentration for this modified
assay, determined by receiver-operating characteristic curve
analysis, was 10 micrograms/L cocaine or BE equivalents. At
this concentration the assay had 94.5% sensitivity and 99.1%
specificity vs gas chromatography-mass spectrometry (GC-MS)
as an acceptable indicator of the true clinical state. The
positive predictive value at a prevalence of 50% was 99%.
Threshold analysis for positives suggested that the 95% confidence
interval for a positive result by the EIA was between 12.5
and 15 micrograms/L and that quality-control samples at 5
and 15 micrograms/L could be run with each batch to certify
the precision around the cutoff. All positive samples must
be confirmed by GC-MS. The sensitivity and specificity of
the overall analysis system (immunoassay screen and GC-MS
confirmation) was 86% and 97%, with known cocaine dosing of
volunteers as the acceptable indicator of the true clinical
state.
P.
Kintz (1996). "Drug testing in addicts: a comparison between
urine, sweat, and hair." Therapeutic Drug Monitoring
18(4): 450-5.
The standard in drug testing is the immunoassay screen, followed
by a gas chromatography/mass spectrometry confirmation conducted
on a urine sample. Recently sweat and hair analyses were proposed
for identifying drug abusers. Specimens can be collected under
close supervision without embarrassment and are not subject
to evasive maneuvers. In contrast with urine, hair analysis
has a wide window of detection, ranging from months to years,
and provides information concerning the severity and pattern
of an individual's drug abuse. Testing individuals for illicit
drugs with sweat patches worn continually would provide effective
coverage for a week. Studies conducted in a detoxification
center have shown that hair analysis is more sensitive for
detecting illicit drug use than is urine screening. My experience
in drug testing is discussed in the light of the existing
literature.
S.
Balabanova, E. Schneider, R. Wepler, B. Hermann, H. J. Boschek
and H. Scheitler (1992). "[Significance of drug determination
in pilocarpine sweat for detection of past drug abuse]." Beitrage
zur Gerichtlichen Medizin. 50: 111-5.
The presence of cocaine, morphine and methadone in sweat samples
obtained after stimulation of the eccrine sweat glands, from
drugs users after six drugs-free days, was investigated. The
stimulation of the sweat elimination was proved using pilocarpine-iontophoresis
every hour for 7 hours. The drugs concentrations were determined
by radioimmunoassay. Consequently, the values measured represent
the sum of the drug and its metabolites. Measurable levels
of cocaine, morphine and methadone were obtained after the
third stimulation of the glands.
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