HSCI 560 Exam 2: Forensic Toxicology

M.J.B Orfila

father of toxicology, made the first attempt to study and categorize poisons

ethanol, cannabis, benzodiazepines and GHB

Most common drugs include

• 0.08–0.15 g/100 mL of blood (or per 210 L of breath) → intoxicated

• ≥ 0.15 g/100 mL → severely intoxicated

It’s illegal to drive if your blood alcohol concentration (BAC) is

schedule 1 (illegal to drive with)

• Has high potential for abuse

• Has no accepted medical use in treatment in the

United States

• Examples: Marijuana, Heroin, LSD and MDMA

schedule 2 (illegal to drive with)

• Has high potential for abuse

• Has currently accepted medical use in treatment in the United States

• Abuse may lead to severe psychological or physical dependence.

• Examples: Cocaine, Codeine, Methamphetamine and PCP

higher

the lower (closer to 1) a schedule, the ______ its abuse potential is

blood

what matrix type is used for Quantitative Alcohol/Drug Testing

urine

what matrix type is used for Alcohol/Drug Screening

vitreous humor

what matrix type is used for Ethanol & Glucose Determinations

hair

what matrix type is used for Chronic Exposure to Drugs and Metal

tissue

what matrix type is used for Heavy Metals (Kidney) | CO and CN (Spleen)

gastric fluid

what matrix type is used for Route of Administration

• Blood coagulation

• Passive diffusion

• Putrefaction

• Simple diffusion

PMR (postmortem redistribution) mechanisms include…

Henry’s law

states that in a closed container, a substance in solution is in equilibrium with the air above it; used for determination of breath

alcohol concentrations

2100

how many mL of breath has same alcohol as 1 mL blood

preliminary breath test (PBT)

•Can be used to establish probable cause

•Results are not admissible in cour

evidentiary breath test

•Results are accurate, precise and quantitative

•Results are admissible in court

• Acetone

• Ethanol

• Isopropanol

• Methanol

what is tested for in alcohol analysis

GC/HS: Headspace-Gas Chromatography Analyzer

what is the instrumentation for alcohol analysis

screening

drug analysis:

•Qualitative or semi-quantitative

•Usually not specific to individual drugs

•Instrumentation: Liquid Chromatography-Mass Spectrometry

confirmation

drug analysis:

•Quantitative

•Analyte specific

•Instrumentation: Gas Chromatography-Mass Spectrometry, Liquid Chromatography-Mass Spectrometry

• Barbiturates

• Benzodiazepines/Z-Drugs

• Cannabinoids

• Muscle Relaxants

• Opioids

• Stimulants

what are the analyte classes for drug analysis screening

LC/TOF-MS: Liquid Chromatography Time-of-Flight Mass Spectrometer

what’s the instrumentation for drug analysis screening

• delta-9 THC

• alprazolam

• amphetamine

• methamphetamine

• fentanyl

what are the top 5 drugs seen at testing sites

Absorption

Distribution

Metabolism

Excretion

what does ADME stand for

additive

effects of combining drugs: When two or more drugs effect on the body is equal to the sum of the individual drugs

antagonistic

effects of combining drugs: when two or more drugs effect on the body is less than the individual drugs

overlapping

effects of combining drugs: when one drug has an effect on the body while the other does not

synergistic

effects of combining drugs: When two or more drugs effect on the body is greater than the sum of the individual drugs

• Euphoria

• Relaxation

• Altered depth/time perception

• Lack of concentration/focus

• Impaired judgement/memory

what can use of cannabis result in

cannabinoid receptors (CB1 and CB2)

what does cannabis act on

CNS depressants

the following are classified as what drug type:

•Alcohol

•Antidepressants

•Antihistamines

•Antipsychotics

•Barbiturates

•Benzodiazepines

•Sedatives

•Muscle Relaxers

• Drowsiness

• Impaired alertness, concentration and coordination

• Impaired judgment

• Impaired short-term memory

• Increased reaction times

• Slurred speech

using CNS depressants can result in

anxiety, depression, seizures and sleep disorders

what can CNS depressants help treat

14

one standard alcoholic drink has how many grams of ethanol

BAC x body weight x V_d

how can you calculate amount of alcohol ingested

CNS stimulants

the following are classified as what drug type:

• Amphetamines

•Cathinones

•Cocaine

•Methamphetamine

• Agitation

• Bruxism

• Increased blood pressure and heart rate

• Increased risk taking

• Intensified emotions

• Pupil dilation

using CNS stimlants can result in what

ADHD, narcolepsy and obesity and can also be used as a local

anesthetic (cocaine)

what can CNS be used to treat

dissociative anesthetics

ketamine and phencyclidine are classified as what type of drug

• Agitation

• Euphoria

• Hallucinations

• Impaired speech and thought

• Increased blood pressure and heart rate

• Poor coordinatio

using dissociative anesthetics can result in what

as anesthetics

dissociative anesthetics can be used…

hallucinogens

the following can be classified as what drug type:

•DMT

•LSD

•MDEA

•MDMA

•MDA

•Mescaline

•Psilocybin

hallucinogens

•These drugs can alter one’s perception of reality

•Many are plant alkaloids

•Typically non-addictive

• Diminished control over what is experienced

• Heightened awareness of sensory input

• Visual illusions

• Synesthesia

using hallucinogens can result in what

inhalants

the following can be classifed as what type of drug (typically abused by younger adolescents due to low cost and ease of availability):

•Aerosol Sprays

•Gases

•Nitrites

•Solvents

• Confusion

• Euphoria

• Hallucinations

• Loss of inhibitions

• Poor coordination

use of inhalants can result in what

narcotic analgesics

the following can be classified as what drug type":

•Codeine

•Fentanyl

•Heroin

•Morphine

•Tramadol

opiate

narcotic analgesic: naturally occurring alkaloids obtained from the

opium poppy (i.e. morphine)

opioid

narcotic analgesic: natural or semi-synthetic alkaloids prepared from

opium as well as synthetic surrogates (i.e. fentanyl)

• Drowsiness/lethargy

• Respiratory depression

• Poor coordination

• Pupil constriction

• Slow reaction times

use of narcotic analgesics can result in what

Horizontal Gaze Nystagmus (HGN)

A condition in which the eyes involuntarily move and jerk in a repeated motion in a side-to-side manner

• CNS Depressants

• Dissociative Anesthetics

• Inhalants

what certain drugs can cause HGN

• Lack of smooth pursuit

• Distinct & sustained nystagmus at maximum deviation

• Angle of onset: BAC = 50 – Angle of Onset

what 6 clues (3 per eye) can we look for to identify HGN

Lack of Convergence (LOC)

This test determines whether the subject can cross their eyes

10

approximately what perecent of the population cannot cross their eyes

• Cannabis

• CNS Depressants

• Dissociative Anesthetics

• Inhalants

what drugs can cause LOC

Walk and Turn (WAT)

The test has two stages: the instruction and walking stage; Subjects are instructed to take nine heel-to-toe steps on a line, to turn around using a series of small steps and then to return taking nine heel-to-toe steps

• Cannot keep balance during instruction phase

• Starts too soon

• Stops walking

• Misses heel-to-toe

• Stepping off line

• Uses arms for balance

• Incorrect number of steps taken

• Improper turn

what clues can be used to see if someone cannot pass the WAT field sobriety test

One Leg Stand (OLS)

The test has two stages: the instruction and balance/counting stage

•Subjects are instructed to stand with one foot on the ground with the other foot raised 6 inches off the ground and count to 30

•This test is done twice (once for each foot)

• Swaying while balancing

• Uses arms to balance

• Hopping

• Puts foot down during test

clues for someone not passing the OLS field sobriety test include

retrograde extrapolation

Estimation of one’s BAC at an earlier point in time from a known value (i.e. blood test) at a later time

• The subject’s elimination rate is between 0.01-0.025 g/100 mL/h

• The subject is in elimination-only mode

what assumptions can be made for retrograde extrapolation