Lecture #2 Introduction to Human Performance Toxicology

What are the three sub-disciplines in the toxicology field?

1. Human performance toxicology
2. Post-mortem forensic toxicology
3. Forensic drug testing

What is the difference between a drug chemist and a toxicologist?

Drug chemists perform qualitative and quantitative analysis of seized drugs while toxicologists perform qualitative and quantitative analysis on drugs in BIOLOGICAL fluids, tissues and complex matrices.

DWI stands for...

Diving While Intoxicated

DUI stands for...

Driving Under the Influence

SFST stands for...

Standard Field Sobriety Test

DRE stands for...

Drug Recognition Expert

Why is blood the preferred specimen in toxicology?

Because blood is most intimately in contact with the central nervous system (CNS), it provides the best information concerning how a drug, its active metabolites, and their concentrations are related to performance impairment. This is why blood is usually the preferred specimen for driving under the influence (DUI) evaluation.

Differentiate between active and inactive metabolites.

Active metabolites produce pharmacological interpretation/insight while inactive metabolites have no pharmacological effect but may indicate time of use.

What is the "per-se" level?

0.08 g/dL etOH in blood.

What is "divided attention"?

Concentrating on more than one thing at a time.

How many phases is the decision to arrest based on?

3

In what phase of the decision to arrest are SFSTs carried out?

Phase III

What does Phase I of the decision to arrest entail?

Initial observation of the vehicle in motion (driving performance) and how the driver stops the vehicle.

What does Phase II of the decision to arrest entail?

Initial observation of the driver, an interview with the driver (in the vehicle), and observation of the physical appearance of the driver.

What does Phase III of the decision to arrest entail?

SFSts and preliminary breath test

What are the three standardized SFSTs?

1. One-leg stand (OLS)
2. Walk and Turn (WAT)
3.. Horizontal Gaze Nystagmus (HGN)

What is horizontal gaze nystagmus?

An involuntary jerking of the eye as they gaze to the side.

What are the three clues for HGN?

1. Lack of smooth pursuit.
2. Sustained nystagmus at max deviation
3. Onset nystagmus prior to 45 degrees

T/F: For HGN, 3 clues indicate BAC of 0.08 g/dL.

FALSE. >4 clues indicate a BAC of 0.10 g/dL

T/F: For WAT, 2 or more clues indicate BAC of 0.10 g/dL.

TRUE

Name some effects of BAC <0.05 g/dL.

1. Divided attention
2. Dynamic visual acuity
3. Complex reaction time
4. Voluntary eye movement

Name some effects of BAC 0.05 - 0.8 g/dL.

Impaired attention, reaction time, info processing, vigilance, tracking, psychomotor performance etc.

What advantages do blood specimens have over breath?

It can be tested for multiple substances and can be re-tested.

What are some advantages of breath as a specimen for BAC testing?

1. Non-invasive collection
2. Collection and analysis done simultaneously
3. Reliable measurements of BAC produced

What are the four types of drugs?

1. Illicit
2. Therapeutic
3. Over-the-counter
4. Herbals or dietary supplements

What are some common drugs found in drivers?

THC, cocaine, hydrocodone, methadone, diazepam, morphine, methamphetamine, carisoprodol, alprazolam, and zolpidem.

T/F: Drug impairment is determined on a case-by-case basis.

TRUE

What are per-se or zero tolerance drug laws?

Laws that make it a criminal offense to have a specified drug or metabolite in the body while operating a motor vehicle.

DEC stands for...

Drug Evaluation and Classification

Who pioneered the DEC Program in the 70s?

LAPD

Who validated the DEC Program in the 1984?

John Hopkins University

What is the DRE's responsibility?

Evaluates suspect's
degree of impairment
and category of drug(s)
responsible for the
impairment
(subjective) into seven
categories

What is the toxicologist's responsibility?

Determines presence of
impairing substance(s)
in biological samples
and provides scientific
evidence that may
support the DRE
opinion (objective)

TAT stands for...

Turn Around Time

What are affected when driving under the influence of drugs?

1. Coordination
2. Reaction Time
3. Judgement
4. Tracking
5. Attention
6. Perception

Besides common drugs, what other drugs tested for in comprehensive drug testing?

1. Antidepressants
2. Antihistamines
3. Sedatives
4. Opioids
5. Hypnotics
6. Muscle Relaxants
7. Anticonvulsants