Download Toxicology PPT

TOXICOLOGY
Miss Colabelli
What is Toxicology?
• Study of how people and other living organisms
interact with drugs and poisons
What is Forensic Toxicology?
• Use of toxicology and other disciplines such as
analytical chemistry
• Pharmacology and clinical chemistry to aid
medical or legal investigation of death, poisoning,
and drug use
• Helps determine CAUSE and EFFECT
relationships
How a drug is broken down
depends on…
• Chemical properties of the drug
• In the body
• Age
• Gender
• Body impairment
• Disease present
• Tobacco/drug use
• Exercise
Metabolism
• Drugs and poisons are
metabolized in the liver by
enzymes
• The enzymes we each have
is determined by our DNA
(enzymes and proteins)
• Enzymes vary person to
person
• Leads to personalized health
care
Half Life – T1/2
• Time it takes for the body to eliminate half of
the drug present
• Can be hours to days or weeks
• Limits how long we can detect a drug or its
metabolites
Toxicity
• Degree to which a substance is poisonous or
can cause injury
• Anything can be a poison in the right dosage
• Too much water dilutes key components of blood
leading to heart and kidney failure
Dose
• The amount of substance taken in by the body
over a short period of time
Acute Toxicity vs. Chronic Toxicity
Acute
Chronic
Single dose
Effects over long periods of time
Effects seen in first 2-4 days
May take years to become evident
Doses typically higher than chronic
Symptoms MAY be reversible
Typically NOT reversible
Research Acute and Chronic toxicity
levels of Aspirin
Acute Toxicity
Chronic Toxicity
Dosage
Above 150mg per kg of
body weight
Below 100mg/kg taken
over days or weeks
Symptoms
Nausea abdominal pain,
organ failure
Lethargy, dizziness,
weakness and later liver
and kidney damage
Lethal Dose
• Measure of the toxicity of a
substance
• LD50 – amount necessary to
kill 50% of the population
• Effect over entire population
• Does not give probability of an
individual dying
• Some may have a greater
sensitivity to a chemical
• Refers to acute exposure
Substance
LD50
Water
90,000
Sugar
29,700
Table salt
3,000
Aspirin
1,750
Detergent
1,260
Ethanol
1,000
Morphine
500
Caffeine
200
Heroin
150
Lead
20
Cocaine
17.5
Cyanide
10
Nicotine
2
Batrachotoxin
0.002
Tetanus or
botulina
0.000001
What is a drug?
• Natural or synthetic
• Compound used for physiological medical effects
• Medicine
• Chemical taken to help deal with generally accepted
medical conditions
• Drug
• Implies chemicals taken for unintended or
uncontrolled use
U.S. Law
• Drug
• Substance intended for use in the diagnosis, cure,
mitigation, treatment, or prevention of a disease or a
substance intended for use as a component of
medicine
• Medicine
• Substance used specifically in treating a disease
Poisons, Toxins, Venoms
• Poison
• Compound designed with specific purpose of
killing cells or organisms
• Toxin
• Subset of poisons
• Produced by living organisms
• Venom
• Toxin injected directly into a victim
Venomous vs. Poisonous
• Venomous organisms use poisons for defense
• Poisonous organisms unintentionally harm by
ingestion, inhalation or skin contact
Two types of Poisons
Corrosive
Metabolic
Destroy tissue on direct contact
Affect chemical functions of cells and
tissues
Act immediately
Block biochemical pathways
Strong acids and bases
CO, Cyanide, heavy metals, Strychnine
Compound
Sulfuric Acid
Hydrochloric acid
Potassium
Hydroxide
Sodium
Hydroxide
Common Names
Uses
Vitriol, sour water
Rain repellent (auto), laundry
perfume/dye-free detergent, drain
opener, car battery
Muriatic acid, spirit or salt
Toiler cleaner/disinfectant, rust and
stain remover, laundry odor
eliminator, tile cleaner, yard and
garden muriatic acid cleaner, fish
pond treatment
Potash, caustic potash,
potassium hydrate
Batteries, automotive cleaner, tile
sealer, household cleaning solution,
oven/BBQ cleaner, drain opener, lawn
“food”, non-aerosol hairspray,
pesticides
Ascarite, caustic soda,
lye
soda
Batteries, car wash
Drug & Poison Pathways
• Absorption into bloodstream
• Ingestion
• Injection
• Inhalation
• Skin/mucus membrane
• Distribution through circulatory system
• Metabolism
• Transformed into manageable waste primarily in the
liver
• Elimination
• Urine, feces, skin, breathing out
Drug Exposure
• Intentionally
• By treating illness or relieving
pain
• Accidentally
• By harmful combinations or
overdoses
• Deliberately
• By harming or killing others, or
suicide
Drugs of Abuse - Hallucinogens
• Often derived from plants
• Effect and intensity varies from person to
person
• Affects perception, thinking, self-awareness
and emotions
• Overdose
• Increased heart rate
• Increased blood pressure
• Panic attacks, anxiety, or psychosis
Drug
Characteristics of Overdose
MDMA (ecstasy)
Increased heart rate and blood pressure, muscle
cramps, panic attacks, seizures, loss of consciousness,
stroke, kidney failure, death
Mescaline
Hallucinations, euphoria, dizziness, vomiting, increase
heart rate, dilated pupils, diarrhea, headaches, anxiety,
irrationality of thoughts
LSD
Dilated pupils, loss of appetite, sleeplessness, increase
in body temperature, increased heart rate and blood
pressure, sweating, dry mouth, tremors, confusion,
distortion or reality, and hallucinations
PCP
Increased heart rate and blood pressure, convulsions,
sweating, dizziness, numbness, and possibility of death
from heart failure, drowsiness which can lead to
accidents. Users sometimes exhibit psychosis
(completely losing touch with reality) that can last for
weeks
Drugs of Abuse - Narcotics
• Bring relief from pain
• Puts person to sleep
• Analgesics
• Relieve pain by depressing nervous system
• Most derived from Opium
Drug
Characteristics of Overdose
Opium
Difficulty breathing, low blood pressure, weakness,
dizziness, confusion, loss of consciousness, coma, cold
clammy skin, small pupils
Heroin, Codeine,
Morphine
Difficulty breathing, low blood pressure, coma, spasms
of the stomach or intestines, constipation, nausea,
vomiting, sleepiness, blue fingernails and lips, death
Methadone
Difficulty breathing, drowsiness, coma, low blood
pressure, muscle twitches, blue fingernails and lips
Oxycodone
Slow, difficult breathing, seizures, dizziness, weakness,
loss of consciousness, coma, confusion, tiredness, cold
clammy skin and small pupils
Drugs of Abuse - Stimulants
• Increases feelings of energy and alertness
• Suppresses appetite
• Depression often results afterwards
• Tend to be highly addictive
• Overdose
• High blood pressure
• Agitation
• Confusion
• Seizures
Drug
Characteristics of Overdose
Amphetamines (speed)
High blood pressure, rapid heart rate, agitation,
irregular heartbeats, stroke seizures, coma, death
Cocaine/crack cocaine
Dangerous rise in body temperature, sweating
tremors, seizures, irregular heartbeats, stoke,
confusion, heart attack, bleeding in the brain,
death
Methamphetamines
Dangerous rise in body temperature, profuse
sweating, confusion, rapid breathing, increased
heart rate, dilated pupils, high blood pressure,
kidney failure, bleeding in the brain, death
Drugs of Abuse – Anabolic
Steroids
• Chemical structure similar to
testosterone
• Promote cell and tissue
growth increasing bone mass
and body muscle
Drugs of Abuse - Depressants
• Affects nervous system by increasing GABA
activity (neurotransmitter)
• Increased GABA causes drowsiness, slowed brain
activity
• Relieves anxiety and produces sleep
• Side effects: slurred speech, loss of coordination
• Includes:
• Tranquilizers, barbiturates, alcohol, valium/xanax
Drugs of Abuse - Alcohol
• Absorbed 20% by stomach and 80% small
intestine
• First effect – frontal lobe judgment
• Concentration
• Normal inhibition
• Second effect with increased consumption is in
the back of the brain
• Language control
• Motor skills
• Body orientation
• Vision
BAC Tests
• Field Sobriety
• Horizontal gaze
• Walk and turn
• One leg stand
• Breath Testing
• Breathalyzer
• Intoxilzer
• Confirmatory Tests
• Gas chromatograph-mass
spectrometer
Why is mercury poisoning also known
as the Mad-Hatter’s disease?
• Hat makers - used a mercury containing
compound
Bacterial Toxins
• Tetanus
• Produced by Clostridium tetani bacteria
• Causes violent muscle spasms
• Botulism
• Produced by Clostridium botulinum bacteria
• Paralyzes muscles
• Causes irreversible damage to nerve ending
• Extremely deadly in small amounts
• Most poisonous biological substance
Heavy Metals and Pesticides
• Heavy metals
• Ingestion, inhalation, through skin, mucous membranes
• Poison
• Pesticides
• Control insects, weeds, fungi, etc
• Toxic
• Other lethal agents
• Hydrogen cyanide (gas chambers)
• Potassium chloride/sodium pentothal (lethal injections)
Poison
Characteristics of Overdose
Pesticides
(DDT, Aldrin, dieldrin)
Interferes with the movement of nerve impulses and
muscular contractions; anxiety, seizures, twitches, rapid
heartbeat, muscle weakness, sweating, salivation,
diarrhea, tearing coma, and death
Lead
Nausea, abdominal pain, insomnia, headache, weight
loss, constipation, anemia, kidney problems, vomiting,
blue coloration along gum line, seizure, coma, and
death
Mercury
Acute poisoning from inhalation causes flu-like
symptoms
Poison
Characteristics of overdose
Arsenic
Within 30 minutes of ingestion produces abdominal pain,
severe nausea, vomiting, diarrhea, muscle cramps,
convulsions, kidney failure, delirium, and death. Chronic
exposure produces skin lesions, headache, personality
changes, nausea, vomiting, diarrhea, convulsions, and
coma
Cyanide
overdose can be fatal in 6-8 minutes after
ingestion. Rapidly causes weakness, confusion, coma and
pink skin from high blood oxygen saturation. Produces
and almond-like odor.
Strychnine
enters the body by inhalation or absorption through eyes
or mouth. Produces, within minutes, body spasms,
temperature rises, violent convulsions, and death
Practice of Forensic Toxicology
• Test for presence and amount of a chemical in a
forensic sample
• Autopsy
• Unidentified compounds
• Chemicals extracted from evidence
Questions that Forensic
Toxicologists answer
• What substance is in the sample?
• What is the unambiguous ID of a chemical?
• How much is present?
• When was the compound taken?
• Is the compound naturally occurring in the
body, was it accidentally or intentionally put
there?
Tests
• Physcico-chem methods
• Titration, density, refractive index, etc
• Spectroscopic
• ID and quantifying based on absorption/emission
• Chromatography/mass spectrometry
• Separate mixture into it’s components; analysis of
components
• Immunoassay
• Antibody-antigen specific reactions
Types of Tests
• Presumptive tests (Field)
• Ex: Marquise reagent
• Confirmatory Tests
• Mass spectrometer
• Immunoassay
• Infrared spectrometer
Samples
• Fluid
• Organs
• Blood
• Skin
• Urine
• Lungs
• Vitreous humor
• Hair
• Oral fluid
• Fingernails
• Semen
• Liver
• Stomach contents
• Kidney
• Bile
• Bone
• Vomit
• Heart
• sweat
• Brain
Blood Samples
• Blood near liver or organs tends to contain higher
concentrations
• Femoral artery
• Urine Samples
• Presence of drugs
• Vitreous humor
• Easily collected
• Stable
• Correlates with
blood data