Forensic Toxicology - Exam 2

drug facilitated crime

use of substances to incapacitate a victim, impair memory, or increase vulnerability so that another crime can occur

drug facilitated sexual assault

DFSA

sedative

reduces irritability and excitement, anxiolytic agents

hypnotic

induces sleep

anesthesia

reversible lack of awareness, reversible state of amnesia, analgesia

15-19

age of women at highest risk for rape

surreptitiously (20%)

suspect will add one or more intoxicating substances into the victim’s food or beverage without the victim’s knowledge

opportunistic (80%)

the victim will have ingested intoxicating substances knowingly, the suspect takes advantage of their altered state

fragmented memory, blackout, vomiting, drowsiness, loss of muscle control

most common symptoms of DFSA

retrograde amnesia

memory loss occurs for events before the onset of brain damage

anterograde amnesia

memory loss occurs for events after the onset of brain damage

anterograde

type of amnesia associated with DFSA

benzodiazepines, ketamine, GHB

drugs that lead to anterograde memory amnesia

blood and urine

sample taken before 24 hours has passed

urine only

sample take after 24 hours has passed

proper seal

a seal that prevents loss, cross transfer, or contamination while ensuring that attempted entry into the container is detectable

incorrect specimen, lack of incident information, low volume

toxicology submission issues

GHB, rohypnol, ketamine, visine

drugs associated with DFSA

7-aminoflunitrazepam

most abundant metabolite in rohypnol

schedule III

GHB schedule

GBL

rapidly converted to GHB in the body, higher bioavailability than GHB

blood for 8 hours, urine for 12 hours

GHB detectability

5 mg/L in blood, 10 mg/L in urine

natural GHB concentration in living person

30 mg/L in blood, 20 mg/L in urine

natural GHB concentration in post-mortem samples

depressant, euphoria, induces tolerance, addiction, weak analgesic

pharmacological properties of alcohol

12 ounces (5%)

serving size of beer

5 ounces (12%)

serving size of wine

1.5 ounces (40%)

serving size of whiskey

14 grams

average grams of alcohol in one drink

individual, environment, dose, pathophysiology, genetics, speed of drinking

factors influencing the concentration of ethanol in the blood after drinking

at the mouth

when does ethanol absorption begin

small intestine

where does majority of ethanol absorption occur

food in stomach, trauma, shock, blood loss

slow rate of absorption of alcohol

empty stomach, carbonated drinks, gastric bypass

fast rate of absorption of alcohol

water

ethanol goes where ______ goes

0.55

women rho

0.68

men rho

serum

has higher ethanol content than blood

vitreous humor

BAC lags behind blood BAC

metabolism

biotransformation of chemicals into water soluble compounds

oxidation, reduction, hydrolysis, cytochrome P450 enzymes

phase I reactions

add bulky side chains, glucuronidation, sulfation

phase II reactions

first pass metabolism

phenomenon of drug metabolism whereby the concentration of a drug is greatly reduced before it reaches the systemic circulation, occurs in the liver

alcohol dehydrogenase (ADH), CYP2E1, catalase

enzymes that metabolize alcohol

aldehyde dehydrogenase

second step of ethanol metabolism

can’t metabolize acetaldehyde

asian flush

antabuse

drug that induces hangovers, prevents ALDH from breaking down acetaldehyde

CYP2E1

present in chronic alcoholics to help them metabolize alcohol faster

elimination

all processes that operate to reduce the effective drug concentration in body fluids 

0.01-0.025

elimination of ethanol range

zero order

kinetics order of the elimination of alcohol

V

Michaelis-menten, number of reactions per second catalyzed per mole of the enzyme

Km

Michaelis-menten, dissociation constant, concentration of substrate that leads to half-maximal velocity

vmax

Michaelis-menten, in this state enzyme active sites are saturated with substrate

michaelis-menten kinetics

high alcohol concentration elimination proceeds at zero order and at very low alcohol concentration elimination proceeds at first order

headspace

refers to the gas phase above the liquid in a vial

Henry’s Law

C1V1 = C2V2, rationalizes alcohol breath testing

amount alcohol = weight x BAC x rho

widmark formula

calculate BAC range by adding BAC to hours passed multiplied by elimination rate

how to do back extrapolation

Grand Rapids Study

the probability of accident involvement increases rapidly at BACs over 0.08 and exponentially increases at BACs over 0.15

GABA and dopamine

ethanol is an agonist to _________

glutamate

ethanol is an antagonist to ___________

higher functions, sensory and fine motor skills, divided attention tasks, gross motor skills

order of effects based on low to high dose

impairment

within-person temporary reduction in performance varying as a function of the pharmacokinetic curve of alcohol, those signs may be subtle and not always visible to the naked eye

intoxication

an advanced stage of impairment when visible signs of alcohol use become apparent

slurred speech

a typical clinical sign of intoxication resulting in imprecise speech articulation including deviation in rate, pitch, and intensity and often an incorrect production of consonants and vowels

mellanby effect

impairment is greater at a given blood alcohol level when the BAC is increasing than for the same BAC when the blood alcohol level in falling

dram shop cases

lawsuit against a bar or restaurant that sells alcoholic drinks brought after one of the establishment’s patrons got drunk and got into an accident

xyrem

prescription form of GHB, used to treat narcolepsy

rho

volume of ethanol distribution