Transcript Pharmacology and Sobriety Testing

Alcohol Impaired Driving
Dr. Bruce A. Goldberger
Professor and Director of Toxicology
Departments of Pathology & Psychiatry
University of Florida College of Medicine
Gainesville, Florida
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Toxicology - What is it?
The study of the nature, effects,
and detection of poisons and
the treatment of poisoning.
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What is a Poison?
Any substance that causes
injury, illness, or death
especially by chemical means.
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TOXICOLOGY in Medicine
What is the Question ???
Document use,
exposure,
impairment, toxicity,
cause of death, …
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“What is there that is not poison? All things are
poison and nothing without poison. Solely the
dose determines that a thing is not a poison.”
– Paracelsus (1493-1541)
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The Role of Alcohol
in Traffic Accidents
(Grand Rapids Study)
Relative Probability
of Causing an Accident
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Traffic Fatalities
Source: NHTSA
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Impairment
Florida Statutes Annotated Section 316.193
1(a) …The person is under the influence of
… any chemical substance…or any
controlled substance…, when affected to
the extent that the person's normal
faculties are impaired.
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Overview
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Introduction to ethanol
Effects of ethanol on driving
Pharmacology of ethanol
Pharmacology issues in DUI cases
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Introduction
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Ethanol is a dose-dependent
depressant drug
Social Lubricant Effects include loss of
inhibitions, altered judgment,
relaxation, increased
confidence, expansiveness,
vivacious personality,
loquaciousness
Depressant Effects Slurred speech, ataxia,
sedation, stupor, coma, death
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Units of Measure
0.08 g/dL
0.08 g/100 mL
0.08 gm%
0.08 % w/v
80 mg/dL (medical)
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Effect of Alcohol
- Central Nervous System 
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Continuum of depression, not discrete effects
Low BAC - apparent stimulant effect (depression
of inhibitory processes)
Increasing BAC: judgment, decision-making,
perception, reaction time are impaired.
Impairment develops prior to overt signs of
intoxication, ataxia, slurring, loss of balance
Mental/physical abilities diminished well before
the appearance of a “classic drunk”
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Stages of Alcohol Intoxication
- Dubowski Subclinical
• Euphoria
• Excitement
• Confusion
• Stupor
• Coma
 Death
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<0.05 g/dL
0.03 - 0.12 g/dL
0.09 - 0.25 g/dL
0.18 - 0.30 g/dL
0.25 - 0.40 g/dL
0.35 - 0.50 g/dL
>0.45 g/dL
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Why 0.08? – The SCIENCE
Virtually all drivers, including
experienced drinkers are impaired at a
BAC of 0.08 (based on a review of
hundreds of scientific studies)
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Common Issues in DUI case?
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Time to peak blood alcohol concentration ?
Validity of a rising BAC defense?
Is the drinking history (amount/time) consistent
with the BAC?
How many drinks did it take to reach the
measured BAC?
What was the BAC at the time of driving/crash
as opposed to the time of testing?
How does alcohol affect driving?
Tolerance?
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Absorption
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Controlled by diffusion
Absorption at each site
depends on quantity of
alcohol, time in contact,
vascularity and surface
area
Small intestine/
duodenum
(large surface area)
Absorption is affected by
gastric emptying
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Variables in Stomach Emptying
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Food in stomach
Meal size/composition
Dose of alcohol
Beverage type
Anatomy of the gut; surgery
Time of day
empties faster in morning
Smoking (delays emptying)
GI motility
Drug use
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Effect of Food on Blood Alcohol
Concentration (BAC)?
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BAC
Empty Stomach
Peak BAC occurs
earlier
Magnitude of BAC is
higher
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Fasted
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Fed
Time
Food in stomach
Food competes with
ethanol for sites in
the small intestine,
slows absorption
Lower peak BAC
Diminished feelings
of intoxication
Shorter time to zero
BAC
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Blood Alcohol Curve
- Time to Peak BAC 
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Single dose, empty
stomach, peak BAC in 1hr
in most individuals
Social drinking situation,
multiple drinks over
several hours, peak BAC
typically within 30 min of
last drink
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Distribution
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Alcohol distributes throughout body
Distributes according to water content
Increased water content, increased alcohol
content
Percentage of total body water (Widmark)
Men approximately 70%
Women approximately 55%
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- alcohol distributes in smaller volume in women,
higher BAC
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A standard drink contains:
1 fluid ounce of 100 proof ethanol
or
½ fluid ounce of pure ethanol
100 proof distilled spirits: 1 fl. oz.
wine: 3-4 fl. oz.
beer: 12 fl. oz.
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Erik Widmark (1889-1945)
First to describe blood alcohol relationship
in quantitative terms: A = C P R
A = DOSE of ethanol
C = CONCENTRATION
P = WEIGHT
R = % total body water
R (men) = 0.51-0.86
R (women) = 0.47-0.64
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Utility of the Widmark Equation
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You may estimate a DOSE of ethanol from
a BAC
You may estimate a BAC from a DOSE
This may be significant in DUI cases to
corroborate/disprove drinking history
Some assumptions are necessary
Assumptions need to be clearly stated by
the expert
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Elimination
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Average elimination:
0.015 g/dL/h
Range: 0.01 - 0.025 g/dL/h
Relatively constant and independent
of concentration
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Retrograde Extrapolation
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Allows estimation of the
theoretical BAC in the linear
(post absorptive phase)
Requires multiple assumptions
Range of elimination rates
to cover population variations
0.01 - 0.02 g/dL/h
Alcoholics up to 0.035 g/dL/h
Liver dysfunction 0.009 g/dL/h
BAC
Time
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Tolerance
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Larger dose needed to achieve desired response
Acute tolerance (Mellanby Effect)
Effects of alcohol are perceived to be greater
when BAC is ascending, rather than descending
Chronic tolerance (Develops over time)
Tolerance lost within 5-7 days of abstinence
Kinetic: faster metabolism
Dynamic: Emetic and sedative effects
Experience: adaptation, speaks slowly, hold on
to chair, etc. to appear less intoxicated
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Summary
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Alcohol produces a continuum of effects,
rather than discrete effects
Interpretation of DUI cases may involve
expert testimony
Alcohol pharmacology plays an important
role
Calculations may be subject to certain
assumptions or generalizations
All assumptions need to be clearly stated by
the expert
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Drug Impaired Driving
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Overview
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Drug vs. Alcohol-related DUI
Effects of drugs other than alcohol
Documentation of drug effects
Interpretation of drug effects
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Two general approaches….
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May require the driver to
be “affected by”
May require the drug to
impair a driver’s ability
to operate a vehicle
safely, incapable of
driving safely or require
a driver to be under the
influence, impaired or
affected by an
intoxicating drug
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Per-se or zero tolerance
drug laws
Make it a criminal
offense to have a
specified drug or
metabolite in the body
while operating a motor
vehicle
Any amount (zero
tolerance) or a specified
level (per se)
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Drug Impaired Driving
- National 
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More difficult to prosecute than alcoholimpaired driving
Under-reported, under-recognized
Drugs are constant factor in traffic crashes
Full impact relatively unknown
9 million people drive after using drugs
Drugs (other than alcohol) found in 17.8%
fatally injured drivers
Source: DHHS and NHTSA
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Drug Impaired Driving
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Drugs detected in 10 to 22% of drivers involved
in crashes, often in combination with alcohol
Drugs detected in up to 40% of injured drivers
requiring medical treatment
Drug use among drivers arrested for motor
vehicle offenses is 15-50%
Highest rates reported among those arrested for
impaired or reckless driving
Source: NHTSA
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Drug Impaired Driving
Drugs associated with impaired driving:
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Cannabinoids/Marijuana
Depressants
- Sedative/hypnotics, therapeutics, muscle
relaxants, antidepressants, antihistamines
Stimulants
- Cocaine, methamphetamine
Narcotic Analgesics
- Morphine, codeine, hydrocodone, oxycodone,
methadone
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Effect of Drugs
on Driving
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Which Drugs Can Affect Driving?
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Any drug that can affect the brain’s
perception, collection, processing,
storage or critical evaluation processes.
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Any drug that affects communication of
the brain’s commands to muscles or
organ systems that execute them.
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For the most part, drugs that affect the
central nervous system (CNS).
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Drug Impairment Issues
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More complex than alcohol
Often in combination with other drugs
and/or alcohol (additive or synergistic
effects)
Scientific literature is complex
May require a toxicologist to interpret the
results and provide an opinion
These complex issues must be explained to
the court using every day language
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Effects of Drugs on Driving
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Coordination
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Tracking
Staying in lane, maintaining
Effects on nerves/muscles distance
steering, braking, accelerating,
manipulation of vehicle
 Attention
 Reaction Time
Divided, not focused. Timeshared task with high demand
Insufficient response
for info processing
 Judgment
 Perception
Cognitive effects, risk
90% of info processed while
reduction, avoidance of
driving is visual. Glare
potential hazards, anticipation,
resistance, recovery, dark and
risk-taking behavior,
light adaptation, dynamic
inattention, decreased fear,
visual acuity
exhilaration, loss of control
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Driving Domains
Sensory/Perceptual
Reaction Time
Psychomotor
Functioning
Executive
Functioning
Source: Barry Logan, Ph.D.
Alertness Arousal
Attention
Processing Speed
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Interpretation and Opinion
of Impairment
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Interpretation Factors
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Empirical Considerations
Epidemiological Studies
Case Reports
Laboratory Studies
Simulator Studies
On-the-Road Driving Studies
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What is the Basis for the
Opinion of Impairment?
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Impairment is based on knowledge of the
drug(s), intended effects, side effects and toxic
effects
The toxicologist can rarely give an opinion based
upon the drug report alone
The opinion may depend on the context of the
case and information gathered by the
investigator (situation, environment,
observations, performance on FSTs, driving
pattern, etc.)
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What the Toxicologist
cannot do….
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Determine impairment in a specific
individual from a drug concentration alone
Determine exactly how much drug was
taken
Determine exactly when a drug was taken
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Drug Interpretation Issues
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Multiple drug use
Tolerance
History of drug use (chronic vs. naïve)
Health
Metabolism
Genetic/Ethnic differences
Individual sensitivity/response
Withdrawal
Put in context of case
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Documentation of
Drug Effects
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Recognition of the
Drug-Impaired Driver
First Choice: DRE Certification
 Systematic, standardized, post-arrest procedure for
Drug Evaluation and Classification (DEC)
 DEC Certified officers are Drug Recognition Experts
 12-step evaluation of behavior, appearance,
psychophysical tests, vital signs, eye measurements
 DRE documents drug signs and symptoms. These are
interpreted by a Toxicologist in a DUID case
 DRE cases provide the court with additional
information
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Recognition of the DrugImpaired Driver
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Non-DRE Officer
Documentation of signs/symptoms in police
report
Toxicologist can use the signs/symptoms to
determine whether impairment was due to
drugs
The toxicologist needs information from many
sources to render an opinion of impairment
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DRE Matrix
Indicators consistent with Drug Categories
Depressants Stimulants
HGN
Hallucinogens
PCP
Narcotics
Inhalants
Cannabis
Present
None
None
Present
None
Present
None
Present (High
dose)
None
None
Present
None
Present
(High dose)
None
Lack of
Convergence
Present
None
None
Present
None
Present
Present
Pupil Size
Normal1
Dilated
Dilated
Normal
Constricted
Normal4
Dilated6
Reaction to
light
Slow
Slow
Normal3
Normal
Little or
none visible
Slow
Normal
Pulse Rate
Down2
Up
Up
Up
Down
Up
Up
Blood
Pressure
Down
Up
Up
Up
Down
Up/Down5
Up
Normal
Up
Up
Up
Down
Up/Down
Normal
Normal
Vertical
Nystagmus
Body
Temperature
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Drug Signs
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Signs and Symptoms:
Depressants
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Confusion
Poor divided attention
Sedation
Droopy eyelids
Slowed reaction times
Memory effects
HGN
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Poor balance
Poor coordination
Unsteadiness
Slurred speech
Disorientation
Low b.p.
Low pulse
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Signs and Symptoms:
Stimulants
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Hypervigilant
Excitability
Anxious
Self absorbed
Agitated
Paranoid
Delusional
Obsessive activity
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Rapid speech
Thought blending
Tremors
Hand wringing
jaw clenching
Dilated pupils
Elevated b.p.
Elevated pulse
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Signs and Symptoms:
Stimulant Withdrawal
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Hypersomnolence
Fatigue
Exhaustion
Withdrawal
Agitated
Paranoia
Delusions
Tremors
Chills
Stimulant withdrawal can
mimic depressant effects
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Signs and Symptoms:
Marijuana
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Relaxed
Sedation
Confused
Poor divided
attention
Memory effects
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Poor balance
Poor coordination
Reddening of eyes
Eyelid tremors
Elevated pulse
Elevated b.p.
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Signs and Symptoms:
Opiates
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Euphoria
Sedation
Confusion
Stupor
Droopy eyelids
Slowed reaction times
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Slowed reflexes
Poor balance
Poor coordination
Constricted pupils
Low pulse
Low b.p.
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Driving Behavior
- Depressants 
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Weaving
Extreme lane of travel
Striking other vehicles
Striking fixed objects
Slow speed
Hit and run
Wrong way driving
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Driving Behavior
- Stimulants 
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Drive-off-the road accidents
Leaving lane of travel
Speeding
High speed collisions
Erratic or risky driving
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Recent Trends in Florida
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Marijuana
Xanax
Methamphetamine
Inhalants Difluoroethane (Dust-off)
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Is The Driver Impaired?
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Positive Toxicology
Drugs in Urine
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Good specimen to screen for large number
of drugs
Typically see metabolites
Indicates drug use within the past 2-3 days
or more
Cannot definitively establish impairment
“Consistent with” or “Explanation for” the
impairment
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Positive Toxicology
Drugs in Blood
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If in the blood, assumed to be affecting
CNS and other target organs
Typically see parent compounds (or both)
Quantitation
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Thank You!
Acknowledgement:
Many slides were provided by Dr. Sarah Kerrigan.
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