Download Drugs and Toxicology

Drugs and Toxicology
Forensic Science
Glatt 2013-2014
Drugs
• Drug- a natural or synthetic substance designed to
affect humans (or other animals) either
psychologically (mind), physiologically (body) or BOTH.
– Non-controlled Substances- Over-the Counter and/or age
restricted yet legal substances
• Legal does not imply safe or non-addictive
– Must use as directed and can be addictive (Caffeine, Tylenol PM,
Nicotine, Alcohol ect…)
• Examples: Aspirin, Cough Medicines, nicotine, alcohol ect…
– Controlled Substances- drugs whose sale, possession, and
use are restricted because of the potential for psychological
and physical dependence and abuse.
• Examples Include: Heroin (I), Cocaine (II), Anabolic Steroids (III),
Xanax (IV), and Codeine (V) ect…
Drug Dependence
• Psychological Dependence- need or desire to use drug to create a sense of
well-being and to escape from reality
– Seek relief from social or emotional stress
– May increase with increased use
•
Physical Dependence- physiological illness or withdrawal effects result from not having
the drug
– Generally considered more severe and can be life threatening
– Illness is due to withdrawal effects
• Body builds tolerance and adjusts to drug being present in system
• Body is thrown out of “equilibrium” without drug present
– Phys. Dependence will increase with increased use
– Withdrawal effects Includes chills, vomiting, stomach cramps, convulsions,
insomnia, pain, hallucinations and even death
• Onset, severity, and duration of psychological and physiological dependency
varies from drug to drug and from person to person
Classification of Controlled Substances
Schedule I—high potential for abuse; no currently accepted medical use in
the U.S.; a lack of accepted safety for use under medical supervision
Examples: heroin (diacetylmorphine), LSD, marijuana, ecstasy
(MDMA)
Schedule II—high potential for abuse; a currently
accepted medical use with severe restrictions; abuse
may lead to severe psychological or physical
dependence
Examples: cocaine, morphine, amphetamines (including
methamphetamines), PCP, Ritalin
Schedule III—lower potential for abuse than the drugs in I or II; a currently
accepted medical use in the U.S.; abuse may lead to moderate physical
dependence or high psychological dependence
Examples: intermediate-acting barbiturates, anabolic steroids,
ketamine
Classification of Controlled Substances
Schedule IV—low potential for abuse relative to drugs in III; a
currently accepted medical use in the U.S.; abuse may lead to
limited physical or psychological dependence relative to drugs
in III
Examples: stimulants and depressants including Valium,
Xanax, Librium, phenobarbital, Darvon
Schedule V—low potential for abuse relative to drugs in IV; currently
accepted medical use in the U.S.; abuse may lead to limited physical
or psychological dependence relative to drugs in IV
Examples: codeine found in low doses in cough medicines
5 Categories of Drugs
1.
2.
3.
4.
5.
Hallucinogens
Narcotics
Stimulants
Anabolic steroids
Depressants
Hallucinogens
• Hallucinogens- substances that can change
normal thought processes, perceptions, and
moods
– Many are derived from plants
– Examples
•
•
•
•
Marijuana (most common)
LSD, PCP, Mescaline
Ketamine (Special K)
MDMA or Ecstasy, GHB, Rophenol or Ruffies (date rape drug)
– Affects of an overdose often include
• Increased heart rate
• Increased blood pressure
• Panic attacks, anxiety, or psychosis
Hallucinogens
Narcotics
• Narcotics- are analgesics or substances that relieve
pain by suppressing the central nervous system.
– Highly addictive
– Includes Opium and its derivatives, heroin (“horse” or
“smack”) and codeine
– Hydrocodone (Vicodin, Lortab), methadone, morphine,
oxycodone (Percocet, OxyContin) and Tylenol 3
(acetaminophen and codeine) are man-made narcotic
painkillers that are often abused
• Most are prescribed yet controlled substances
– Effects of overdose are related to slowed central nervous
system
• Difficulty breathing, low blood pressure, confusion, sleepiness,
clammy skin, small pupils, coma, and death
Narcotics
Stimulants
• Stimulant- are substances that increase the
actions of the central nervous system
–
–
–
–
Highly addictive
Increased energy, alertness
Suppressed appetite and fatigue
Increased anxiety and depression when drug wears off
•
Overdose affects include high blood pressure, agitation, confusion,
seizures
– Examples include caffeine, nicotine, amphetamines (
uppers or “bennies”, methamphetamine (“speed” or
“crank”), cocaine, and crack (recrystallized cocaine)
Stimulants
Anabolic Steroids
• Anabolic Steroids- are substances that promote cell
division and tissue growth
– Created in laboratory
• Originally used to treat hypogonadism (condition in which testes
produce low amounts of testosterone)
• Also currently used to treat delayed puberty, impotence, and
muscle wasting caused by HIV infection.
– Commonly used illegally and abused by weightlifters and
other athletes.
– Mild side effects include increased acne, increased body
hair, balding
– Severe side effects include high blood pressure, increased
cholesterol levels, impaired fertility in males, blood
clotting, kidney and liver cancers, and heart attacks
Depressants
• Depressants- are substances that decrease the
action or suppress the central nervous system.
– Often prescribed to lower anxiety or promote sleep
– Reduce body functions by increasing the activity of
the neurotransmitter (brain chemical) called GABA
– Examples include alcohol, barbituates,
benzodiazepines
– Side effects include slurred speech, loss of
coordination, and state of intoxication similar to that
of alcohol
– Overdose may slow heart rate, breathing rate, and
cause coma or death
Drugs and Crime
• In US, as much as 75 % of evidence being
examined in forensic laboratories is
considered drug related
– Either drugs themselves or evidence from drug
related crimes
TOXICOLOGY
• Forensic toxicology- is the combined study of
chemistry, biology, and physiology concerned with the
study of the adverse effects of chemicals on living
organisms.
– A toxicologist is a scientist or medical personal who
specializes in the study of symptoms, mechanisms,
treatments and detection of drugs, toxins, and venoms in
the body
• Cause and effect relationship of ingesting drugs, toxins or venoms
is also determined
– State of inebriation due to alcohol or drug use
– Poisoned or natural caused death
– Role or influence of alcohol or drugs in a perpetrator or victims actions
• also studies the harmful effects of chemical, biological and
physical agents in biological systems that establishes the extent of
damage in living organisms.
Forensic Toxicology
Postmortem—medical examiner
or coroner
Criminal—motor vehicle
accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial,
catastrophic, terrorism
Aspects of Toxicity
Toxicity- the degree to which a substance is poisonous or
can cause injury, or has an effect upon someone (drugs)
1.
2.
3.
4.
Dosage or concentration
The chemical or physical form of the substance
The mode of entry into the body
Body weight and physiological conditions of the victim,
including age and sex
5. The time period of exposure
6. The presence of other chemicals in the body or in the
dose
SYNERGIZING EFFECT – 2 Drugs mixed together leads to an increased effect of
both drugs when taken separately
– Alcohol and other depressants
– Dangerous risk of overdose
Lethal Dose
LD50 refers to the dose of a substance
that kills half the test population,
usually within four hours
Expressed in milligrams of substance per
kilogram of body weight
Toxicity Classification
Human Specimens for Analysis
• Blood
• Urine
• Vitreous humor of
eyes
• Bile
• Gastric contents
• Liver tissue
• Brain tissue
• Kidney tissue
• Hair/nails
Techniques Used in Testing
• Acid or Base
– Initial test can narrow down the type of substance
or drug present.
Techniques Used in Testing
SCREENING TESTS
– Presumptive Tests – chemical indicators are used to test for the possible presence of
certain drugs
• Indicators detect and “indicate” the possible presence of drug or poison by turning a specific color
– Marquis Solution (formaldehyde in sulfuric acid)
» Turns purple in presence of heroin, morphine, and most opium derivatives (narcotics)
» Also turns orange-brown when mixed with amphetamines and methamphetamines
– Dillie-Koppanyi
» Turns violet-purple in presence of barbituates
– Duquenois-Levine
» Turns purple in the presence of marijauna
– Van Erk (3 solution test)
» Turns blue purple in the presence of LSD (“acid”)
– Scott Test (3 solution test)
» Indicates or detects cocaine
– Thin-Layer Chromatography
– Gas chromatography
– Thin Layer Chromatography
Screening tests are not admissible in court as certain substances can result in false
positives. Initial screening tests are therefore followed by confirmatory tests
Techniques Used in Testing
Confirmation Tests
• Gas Chromatography/Mass Spectrometry
– Gas Chromatography- used to separate the
individual compounds in a mixture or solution
– Mass Spectroscopy- used to conclusively identify
unknown samples.
• Compounds are bombarded with a stream of electrons
causing them to break apart into fragments
• Mass to charge (M/Z) of each fragment is measured
and graphed
Alcohol—Ethyl Alcohol (C2H5OH)
• Most abused drug in America
• About 40 percent of all traffic deaths are alcohol-related
• Toxic—affecting the central nervous system, especially the
brain
• Colorless liquid, generally diluted in water
• Acts as a depressant
• Alcohol appears in blood within minutes of consumption;
30–90 minutes for full absorption
• Detoxification—about 90 percent in the liver
• About 5 percent is excreted unchanged in breath,
perspiration, and urine
BAC: Blood Alcohol Content
• Expressed as percent weight per volume of blood
• Legal limit in all states is 0.08 percent
Parameters influencing BAC:
• Body weight
• Alcohol content
• Number of beverages consumed
• Time since consumption
– Alcohol is metabolized at a rate of approximately 1
drink per hour.
BAC Calculation
Blood Alcohol Content
.08 legal limit
Male
BAC =
Female
BAC =
0.071  (oz)  (% alcohol)
body weight
0.085  (oz)  (% alcohol)
body weight
Field Tests
• Preliminary tests—used to determine the degree
of suspect’s physical impairment and whether or
not another test is justified
– Psychophysical tests—three basic tests:
• Horizontal gaze nystagmus (HGN): follow a pen or small
flashlight, tracking left to right with one’s eyes. In general,
wavering at 45 degrees indicates 0.10 BAC.
• Nine-step walk and turn (WAT): comprehend and execute
two or more simple instructions at one time
• One-leg stand (OLS): maintain balance; comprehend and
execute two or more simple instructions at one time
Bacterial Toxins
• Botualism
• Tetanus
• anthax
Heavy metals
• Arsenic
• Lead
• Mercury