ALCOHOL
(ETHANOL)![]()
Drug class:
CNS Depressant
Retention Time:
Depends on the amount of ethanol consumed. In general
terms, it takes approximately 1 hour to absorb from the
stomach into the blood. From there the blood alcohol decreases
at about .015 gm/dL (gm %) per hour. This means it takes
the body about 2 hours after absorption to metabolize
a 12 oz. beer.
Alcohol Equivalencies:
¨ú oz. pure ethanol = 1.5 oz. 86 proof = 5
oz. glass of wine = 1-12 oz. beer. Ingesting one of these
equivalences could result in a blood alcohol of approximately
.03 gm/dL and would require approximately 2 hours post
absorption to eliminate.
The number of drink equivalents consumed within a 4 hour
period to reach a corresponding alcohol level are indicated
below (approximations only).
|
| |
#
Of Drinks
|
Alcohol
Level (gm/dL) |
| |
2
3
4
5
6
7
8 |
.02
.05
.08
.11
.14
.17
.20 |
| |
|
| |
| Blood Alcohol Levels
and Impact on Behavior: (Approximation Only) |
Slurred
Speech
Loss of Equilibrium
Drowsiness
Under the Influence
Coma
Respiratory Collapse |
.02 - .04 gm/dL
.05 (Colorado Impaired Limit)
.06
.08 (Colorado legal limit)
.40
>.50 |
|
| |
Relationship
of Blood Alcohol Level to Urine Levels
Since ethanol levels are being determined on random urine
samples there is no way to determine the stage of metabolism,
i.e. absorption or elimination. For this reason an average
conversion factor of 1.3 is used to convert the urine
ethanol level to a corresponding blood level (Estimation
only).
False Positives:
EIA is optimized to detect ethanol; however other alcohols
or volatiles (isopropanol, methanol, acetone, etc.) at
high levels may cross-react. Gas Chromatography head space
(GC/HS) will specifically identify and quantitate ethanol.
In addition a urine sample containing both yeast (contamination
or infection) and glucose (diabetes) will result in fermentation
within the bladder or sample bottle thus producing ethanol. |
| |
Forensic
Laboratories Ethanol Cutoff Level for urine samples =
.05 g/100mL ? Only levels greater than this value will
be reported detected.
|
AMPHETAMINES![]()
Drug class: ![]()
Central Nervous System Stimulant
Retention
Time: ![]()
Schedule II
Alcohol Equivalencies:![]()
Speed, Crank, Ice, Crystal Meth, Uppers, etc.
Retention:
(Detection) Times: ![]()
24-96 Hours |
| |
| |
Chemical
Name
|
Trade
Name |
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Amphetamine
(A)
Methamphetamine (MA)
Benzphetamine
Selegiline |
Dexedrine,
Benzedrine
Desoxyn, Methedrine
Didrex
Eldepryl |
+
+
+
+ |
A
MA & A
MA & A
MA & A |
1000
1000
1000
1000 |
0.5
0.5
0.5
0.5 |
| |
|
| Compounds which are
metabolized to MA & A |
| |
| Common
Prescription (P) and Over-the-Counter (OTC) Drugs |
EIA
(EMIT) |
TLC |
| |
Pseudo
ephedrine (OTC)
Ephedrine (OTC)
Phenylpropanolamine (OTC)
Phentermine (P)
Methylphenidate (P)
Fenfluramine (P)
MDA / MDMA
Caffeine (OTC) |
Sudafed,
etc.
Primatene, Bronkaid, etc.
Contac, Dexatrim, etc.
Fastin, Ionamin
Ritalin
Pondimin
Ecstasy (street / club drug)
No Doz |
+
+
+
+
+
+
+
- |
-
-
-
-
-
-
-
- |
| |
|
| Compounds which are
metabolized to MA & A |
NOTES:
1) Thin-layer chromatography (TLC) will specifically identify
amphetamine and methamphetamine and rule out over-the-counter
and prescription drugs.
2) TLC can specifically identify prescription and over-the-counter
drugs (as indicated by the underlined drugs in the section
above) if requested.
3) Albuterol (Ventolin), Alupent and other asthma inhalers
will not test positive for amphetamines.
|
| |
|
BARBITURATES![]() |
Drug
class:
CNS Depressant
DEA Classification:
Schedule II (Phenobarbital – Schedule IV)
Retention Times:
24-48 Hours (Phenobarbital: 2-3 weeks
|
| |
Chemical
Name
|
Trade
Name |
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Phenobarbital
Secobarbital *
Pentobarbital *
Butalbital *
Amobarbital *
Aprobarbital * |
Luminal, Donnatal, Mudral, etc.
Seconal
Nembutal
Fiorinal (contains codeine)
Amytal
Alurate |
+
+
+
+
+
+ |
+
+
+
+
+
+ |
300
200
500
500
2000
200 |
1.0
0.5
0.5
1.5
1.0
1.5 |
| |
|
* Reported as Barbiturate positive - Not Phenobarbital
|
| NOTES
: Notice that barbiturates are detected at different
levels both upon screening and confirmation. |
Additional
Notes:
1) EIA and TLC are specific for barbiturates - No cross-reacting
compounds have been found.
2) If specific identification of a barbiturate (other
than phenobarbital) is absolutely necessary, a GC/MS can
be performed.
|
BENZODIAZEPINES![]() |
Drug
class:
Antidepressants, Sedatives, and Hypnotics
DEA
Classification:
Schedule IV
Street Names:
Downs, Nerve Pills, Tranks, etc.
Retention (Detection) Times:
Therapeutic Dose-24-72 Hours; Chronic use over a period
of months to
Years can yield retention times of 4-6 weeks. |
| |
Chemical
Name
|
Trade
Name |
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Diazepam
Chlordiazepoxide
Oxazepam
Chlorazepate
Temazepam
Prazepam
Flurazepam
Lorazepam
Alprazolam
Triazolam
Flunitrazepam
Clonazepam
Oxaprozin * |
Valium
Librium
Serax
Tranxene
Restoril
Centrax
Dalmane
Ativan
Xanax
Halcion
Rohypnol (Date Rape Drug)
Clonopin
Daypro |
+
+
+
+
+
+
+
+
+
+
+
+
+ |
+
+
+
+
+
+
-
-
-
-
-
-
- |
200
3000
200
300
300
300
300
400
300
300
300
300 |
0.1
0.1
0.1
0.1
0.1
0.1 |
| |
|
* Not a benzodiazepine - A false positive (Can be ruled
out by TLC)
|
NOTES
:
1) The benzodiazepines which can be detected by TLC are
all metabolized in urine to common metabolites, oxazepam
and/or nordiazepam, therefore the parent drug cannot be
determined. Other chromatography methods, such as GC/MS,
upon routine analysis also detect only the benzodiazepines
which metabolize to these common metabolites.
2) In most cases a specific request must be made to confirm
alprazolam, triazolam, lorazepam, clonazepam, flunitrazepam
by GC/MS or other chromatographic methods.
3) Enzyme immunoassay (EIA) methods detect a broad spectrum
of benzodiazepines, however confirmation methods generally
detect only limited numbers of benzodiazepines.
|
COCAINE
(BENZOYLECGONINE)![]() |
Drug
class:
CNS Stimulant
DEA Classification:
Schedule II
Street Names:
Coke, Crack, Rock, Snow, etc.
Retention (Detection) Times:
24 – 96 Hours |
| |
Chemical
Name
|
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Benzoylecgonine
*
Cocaine * |
+
+ |
+
+ |
300
300 |
0.4
1.0 |
| |
|
* Benzoylecgonine is a specific primary metabolite of
cocaine. It is stable in urine and is therefore used for
the specific detection of cocaine. Parent cocaine can
be detected in urine however it is unstable and is rapidly
converted to benzoylecgonine.
|
NOTES
:
1) Both the EIA and TLC methods are specific for benzoylgonine.
Other drugs such as Lidocaine, Novacain, Benzocaine, etc.
do not cross-react to yield false positive results.
2) Studies indicate that passive inhalation (second hand
smoke) of smoke from crack cocaine does not yield positive
results at cutoff levels (0.3 mcg/mL) used for EIA screening.
3) It is possible to test positive for cocaine from an
individual who has kissed someone who has just snorted
cocaine and traces still remain in the nasopharynx area
thus cocaine would be present in saliva transferred to
the other individual.
|
MARIJUANA
(THC)![]() |
Drug
class:
CNS Depressant, Hallucinogen
DEA
Classification:
Schedule I
Street Names:
Grass, Pot, Hashish
Retention (Detection) Times:
: (Based upon a screening cutoff of 50 ng/mL or greater)
Light Smoker 1-3 Days
Moderate Use (~4 times/week) 3-5 Days
Heavy Smoker (daily) 10 Days
Heavy, Chronic use (5+ joints/day) 10-21+ Days
Oral Ingestion 1-5 Days
Elimination
Half-Life:
18-24 hours - Essentially one-half of ingested marijuana
is eliminated every
18-24 hours regardless of amount ingested. Once smoking
is ceased, elimination
occurs at the same rate.
Analytical
Note:
EIA screening methods are usually optimized to detect
delta-9-THC-COOH, a primary
metabolite of marijuana, but also react with other cannabinoid
metabolites therefore
results are expressed in terms of total cannabinoids.
Confirmatory chromatographic
methods (TLC, GC/MS, etc.) detect delta-9-THC-COOH only,
which constitutes
approximately 30-50% of the total cannabinoid level. Forensic
Laboratories reports
semi-quantitative values for THC which represent an estimation
only of the true
quantitative total cannabinoid level.
Interpretation
of Results
Urinary concentrations of THC are very difficult to interpret
due to variables such as dosage of THC ingested, frequency
of prior use, timing of urine collection relative to last
exposure to marijuana, rate of release of stored cannabinoids
in adipose tissue, and concentration of urine. Therefore
the detection of THC metabolites in urine is only an indication
of past marijuana uses and is not related to the degree
of intoxication or impairment.
|
| Interpretation
of THC Semi quantitative Values: |
| |
THC
Result
|
Interpretation |
| |
>
150 units
100-150 units
50-100 units
< 50 units |
High Dosage-Acute
dosage probably within 3-10 days.
Moderate Dosage-Ingestion occurred probably within
3-21 days.
Low Dosage-Difficult to determine time of use as
chronic habitual users can
excrete THC values in this range for 21-30 days
or longer.
Cannot rule out chronic users, passive inhalation,
ingestion of low quantity, or
dilute specimen. |
| |
|
Semi-quantitative THC values are of little use when determining
possible renewed marijuana use. A helpful method of answering
this question is to normalize the cannabinoid concentration
to the urine creatinine value of the sample. Random urine
specimens contain varying amounts of creatinine depending
on the concentration of the urine. This THC/creatinine
ratio provides a means to eliminate the urine dilution
problem when interpreting THC values. Therefore, in general,
an increase of >50% in the THC/creatinine ratio above
the previous sample is considered to indicate a new episode
of drug exposure.
|
METHADONE
/ METHADONE METABOLITE![]() |
Drug
class:
Narcotic Analgesic
DEA Classification:
Schedule II
Retention (Detection) Times:
24-72 Hours |
| |
Chemical
Name
|
Trade
Name |
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Methadone
Levomethadyl (LAAM) *
Methadone Metabolite |
Dolophine
ORLAAM |
+
±
+ |
+
-
+ |
300
300
300 |
0.5
N/A
0.5 |
| |
|
* The EIA method for methadone will detect LAAM at high
concentrations. LAAM is quickly metabolized therefore
parent LAAM will not always be detected.
|
NOTES
:
1) All EIA negative methadones and/or methadone metabolites
are confirmed by TLC.
2) Some individuals metabolize methadone at increased
rates and may test negative for both methadone and methadone
metabolite.
3) All positive methadone metabolites from California
Methadone Maintenance programs are confirmed by TLC.
|
| Interpretation
of Results: |
| |
Methadone
|
Meth.
Metab. |
Interpretation |
| |
+
-
+
- |
+
+
_
- |
Methadone
was ingested due to presence of metabolite.
Methadone ingested due to presence of metabolite;
Parent methadone
below detection limit.
Methadone ingested and metabolite below detection
limit; or if
creatinine is 0.0 (water) then methadone med. was
poured directly into
urine; or if creatinine is present then methadone
med. may have been
poured into an alternate urine specimen.
Methadone was not ingested; or methadone and methadone
metabolite
were below the detection limit. GCMS can be utilized
to increase
sensitivity. |
| |
|
OPIATES![]() |
Drug
class:
Narcotic Analgesic
DEA Classification:
Controlled
Retention (Detection) Times:
24-72 Hours
|
| |
Chemical
Name
|
Trade
Name |
Results
Reported |
Detection
Limits |
| EIA
|
TLC |
(ng/mL)
EIA |
(mcg/mL)
TLC |
| |
Codeine
Morphine
Diacetylmorphine
Hydrocodone*
Hydromorphone*
Oxycodone* |
Empirin, Tylenol 2-5
Roxanol
Heroin
Vicodin, Hydrocodan
Dilaudid
Percodan |
+
+
+
+
+
- |
+
+
+
+
+
+ |
300
300
300
1000
1000
10000 |
0.5
0.5
0.5
2.0
1.0
1.0 |
| |
|
* These drugs may not test positive at therapeutic levels.
** Thin-Layer chromatography (TLC) confirmation will specifically
identify which opiate was detected.
*** Notice that hydrocodone, hydromorphone, and oxycodone
require higher levels to be present in urine
than codeine or morphine to screen positive.
|
| |
| Interpretation
of Results |
| |
| Possible
Opiate Source |
| |
| |
Prescription |
Prescription |
|
|
|
Test Result |
Codeine |
Morphine |
Heroin |
Poppy
Seeds |
| |
Codeine
(C) only
Morphine (M) only
C > M
M > C
M = C |
X
X
X
X
X |
X |
X
X |
X
X
X |
| |
|
NOTES :
1) If absolutely necessary, information about the possible
opiate source may be determined by quantitating codeine
and/or morphine by GC/MC.
2) 6-monoacetylmorphine may be performed by either TLC
or GC/MS to specifically identify heroin as the opiate
source.
3) Free morphine is reported when the urine is tested
without hydrolysis* and total morphine is reported when
the urine is hydrolyzed.
* A procedural step during opiate analysis.
|
| Forensic
Laboratories is certified and licensed by the Department
of Health & Human Services Health Care Financing Administration
(CLIA ¡¯88, CLIA ID# 06D0982654). |
THC
INTERPRETATION![]() |
The values
that Forensic Laboratories report for THC are only to
be interpreted as an estimation of the quantitative weight
per volume measurement. Urinary THC values are very difficult
to interpret due to variables such as frequency of marijuana
use, amount used, urine concentration, body weight, etc.
Therefore, positive urine specimens for THC merely indicate
that marijuana was ingested at some time in the past.
Based upon our experience using these values, the urine
content of THC can be interpreted as follows:
50-100 ng/ml= Low
100-150 ng/ml= Moderate
Greater than 150 ng/ml= High
The use of these values in determining whether or not
the amount of THC detected can be associated with drug
effects is very difficult to answer. Because analysis
of a single urine specimen cannot distinguish between
very recent use and chronic use, the time of use cannot
be determined with any certainty. (Blood draw analysis
analyzing for unmetabolized THC can be performed for an
approximation of THC time of last use.) Therefore these
THC units should not be used for ascertaining recent marijuana
use based upon a single determination, but for following
the progression over time of multiple THC values. Scientific
studies have shown that THC is eliminated from the body
at a relatively constant rate. The rate is defined in
terms of the amount of time it takes for one-half of the
drug to be eliminated from the body. The best estimate
for this THC half-life is 18-24 hours. This means that
half (50%) of the THC taken will be gone after 1 day,
75% will be gone after 2 days, 87.5% will be gone after
3 days, et cetera. Therefore any precipitous increase
in THC values following a period of declining values may
be an indication of renewed THC use.
NOTES
:
The urine THC values offer preliminary interpretation
information. Forensic Laboratories strongly recommends
consulting a Board Certified Toxicologist for proper interpretation
of THC levels prior to any administrative action.
|
| |
| DRUG
RETENTION TIMES |
| |
| CANNABINOIDS |
DETECTION
TIME |
EXPLANATION
OF DRUG ENFORCEMENT AGENCY CLASSIFICATION |
| |
Light
smoker or acute dosage
Moderate Use(4 time/week)
Heavy Smoker (daily)
Oral Ingestion |
1-3
days
3-5 days
10 days
10-21+days
1-5 days |
I
II
III
IV |
Illicit
drugs with no medical use; high potential for abuse
Prescription drugs with high potential for abuse
and physical dependence
Drugs with less abuse potential than schedule II;
have moderate to low physical dependence, but may
have high psychological dependence
Prolonged use of these drugs may lead to limited
physical or psychological dependence; lower abuse
potential than schedule III. |
| |
|
NOTES :
: Interpretation of retention time must take into account
several variables such as drug metabolism, half-life,
patient¡¯s physical condition, fluid intake, method and
frequency of ingestion, drug dosage, etc. These are general
guidelines only. For questions, please call Forensic Laboratories
at (303) 469-8042.
|
| Urine
Creatinine Interpretation THC/Creatinine Normalization
|
| Introduction |
THC is
one of the numerous cannabinoid chemicals present in marijuana
as well as the primary psychoactive ingredient. Cannabinoid
metabolites appear in urine within two to four hours after
smoking marijuana and may persist up to 30 days (at the
50 ng/mL cutoff concentration) depending upon a person's
previous pattern of abuse. In general, infrequent use
of marijuana may only be detected for 1-3 days after use.
Regular use, several times per week, may be detected for
7-10 days, while chronic use of marijuana may be detectable
for up to 30 days. Routine passive inhalation to marijuana
will not cause a positive urine drug test for THC at either
a 50 ng/ml or 20 ng/mL cutoff
concentrations.
The measurement of creatinine concentrations is an important
variable to monitor when attempting to determine if an
individual has abstained from marijuana between successive
urine specimens. The concentration of the THC metabolite,
carboxy-THC, can fluctuate from day-today depending upon
a persons fluid intake. Increased fluid intake will lower
both the carboxy-THC and creatinine concentration in a
urine specimen while dehydration will have the opposite
effect. Calculation of the carboxy-THC to creatinine normalization
neutralizes any change in the carboxy-THC concentration
due to variation in a person¡¯s hydration state. This calculation
makes it possible to compare urine specimens to establish
if renewed use of marijuana has occurred.
|
| Semi-quantitative
EIA Results |
The enzyme
immunoassay (EIA) values reported by Forensic Laboratories
for THC (marijuana) are only to be interpreted as an estimation
of the concentration of total cannabinoids (marijuana
metabolites) present in a urine specimen. Urinary cannabinoid
values are difficult to interpret due to variables such
as frequency of use, duration of use, amount used, and
an individual's liquid consumption. Therefore, positive
EIA results for THC (cannabinoids) indicate use of marijuana
but numerous additional considerations, such as THC/Creatinine
normalization are required to establish renewed or continued
use.
Based on our experience at Forensic Laboratories, the
following offers some general guidelines for interpreting
laboratory EIA results:
|
| |
EIA
Value
|
Use
Pattern |
| |
>
500
250-500
< 250 |
Possible
recent/ high use
Possible continued elimination in chronic use or
recent use in infrequent user
Possible terminal elimination in chronic use or
recent use in infrequent user. |
| |
|
| Urine
Creatinine Interpretation THC/Creatinine Normalization
(Con¡¯t) |
The
use of the EIA values provides preliminary clinical information
for single use of marijuana. Because the analysis of a
single urine specimen cannot typically distinguish between
very recent use and chronic use, the exact time of use
cannot be determined with any
certainty. A more reliable determination of renewed use
of marijuana requires the comparison of the THC/Creatinine
normalization between multiple urine specimens. This normalization
can be calculated by dividing the ¡°THC¡± value by the Creatinine
value then multiplying by 100. In general, an increase
of more than 50% in the THC/Creatinine normalization between
two urine specimens provides clinical evidence of possible
renewed use. If the THC/Creatinine results are to be used
for punitive or administrative purposes, GC/MS
confirmation analysis must be performed to provide a definitive
interpretation of renewed marijuana use.
The following graph is actual data from a client with
a chronic history of smoking marijuana who was being routinely
monitored for drug use: |
 |
The
top curve represents the THC (cannabinoid) values based
upon the EIA analysis while the bottom curve is a plot
of the respective "THC/Creatinine" Normalization.
Although the graph shows an increase in the THC value
from 180 to 258 between days 14 and 17, respectively,
the corresponding normalization actually decreased from
102 to 82. Thus, although the THC values might have caused
concern of renewed marijuana use, the THC/creatinine normalization
actually decreased. This decrease in the normalization
is more indicative of continued elimination of marijuana.
|
| Urine
Creatinine Interpretation THC/Creatinine Normalization
(Con¡¯t) |
| A
plot of the THC and THC/creatinine normalization from
another subject yields a different interpretation: |
 |
| The data
revealed decreasing "THC" values of 200 and
150 for days 12 and 14, respectively. In contrast, the
corresponding THC/Creatinine normalization show a sharp
increase from 75 to 536, respectively. Although the THC
values do not suggest renewed use between the two urine
specimens, the normalized values provide strong clinical
evidence of renewed use. For conclusive evidence, only
these two urine specimens need to be confirmed by GC/MS
analyses. If the increase in the normalization is further
substantiated with GC/MS analyses, then it can be concluded,
with scientific certainty, that the individual had used
marijuana between the two urine collections.
Finally, although an initial EIA positive test in combination
with an EIA semi-quantitative positive result provides
preliminary interpretation information; clinical consideration
and professional judgment should be considered for more
reliable interpretation. Forensic Laboratories strongly
recommends consulting with a toxicologist and gas chromatography/mass
spectrometry (GC/MS) confirmation prior to any administrative
or legal action. |
