Examples: Marijuana, hashish, hash oil
Medical uses: Treatment of nausea and vomiting due to cancer chemotherapy.
Effects attractive to abuser: Euphoria, intensified sensual and
Adverse effects: Paranoia, panic, impairment of memory and ability to
perform tasks, distorted perception of time, physical and psychological
How abused: Smoked in cigarettes or pipe; occasionally eaten as
ingredient baked into confections.
Typical urine detection cutoff level: 100 ng/mL or 20 ng/mL (optional)
Period detectable after last dose: This is highly variable. A one joint
per week user has detectable levels of cannabinoids form 7 to 34 days,
while a heavy daily user may be detected from 6 to 81 days after last use.
Substances causing false positive results: none reported. A screen
detection cutoff level of 20 ng/mL, requested by some laboratory clients,
may produce false positives due to passive inhalation of marijuana smoke,
but this is controversial.
At the cutoff level of 100 ng/mL, persons exposed passively to the smoke
of others by virtue of being in the same room with abusers should be
negative on urine drug screen, although more sensitive chemical techniques
(such as gas chromatography/mass spectrometry, which has a sensitivity of
10 ng/mL) may demonstrate the drug in such an individual's urine.
Examples: Cocaine hydrochloride is the typical form used by abusers who
ingest the drug by snorting the granular form into the nose; it can also be
dissolved in water and injected intravenously. Cocaine base is available in
a waxy cake form ("rock" or "crack") which is vaporized with a torch and
the vapors inhaled through a tube.
Medical uses: Used almost exclusively by ear, nose and throat doctors to
produce local anesthesia and control blood loss during minor nasal
Effects attractive to abuser: Euphoria, increased ability to
concentrate, increased alertness, heightened ability to perform
intellectual and physical tasks, sexual stimulation, heightened
sociability, enhanced self-confidence.
Adverse effects: Restlessness, nervousness, tremor, convulsions,
disturbances in heart rhythm, psychological dependence, myocardial
infarction, sudden death.
How abused: Snorted, injected, or smoked (see above).
Typical urine detection cutoff level: 300 ng/mL
Period detectable after last dose: 8-48 hours
Note: The laboratory detection of cocaine is performed by analyzing the
urine for the presence of benzoylecgonine, a substance produced by the
body's chemical detoxification of cocaine. Continuous conversion of cocaine
to the metabolite occurs in voided, standing urine specimens (even with
fluoridation and refrigeration) unless the specimen is kept at acid pH
(<5). This may give the appearance of a negative specimen "turning
positive" during storage, if the initial level of the metabolite was too
low to trigger the screen in the fresh specimen. In truth, the specimen was
positive all along, of course.
Substances causing false positive results: none reported; however, some
legal South American herbal teas may contain small amounts of coca leaf
extract, which may trigger a positive test in an "innocent" subject. Please
note that cocoa, cacao, and Coca Cola are all completely unrelated to coca,
which is the source of cocaine.