Forensic Toxicity

Question 1

what is medical examiner system

Answer 1

its headed by a forensic pathologist (MD)

Question 2

what is a coroner system

Answer 2

it may not be headed by a physician

Question 3

what are 2 things that you do in clinical toxicology

Answer 3

• emergency screening (overdose)

- therapeutic drug monitoring

Question 4

when do you do clinical toxicology testing

Answer 4

if it is likely to influence treatment of the patient

Question 5

why do we do forensic toxicology

Answer 5

for legal purposes

Question 6

what are 4 examples of forensic toxicology

Answer 6

• postmortem (cause of death)
• impaired driving/sexual assault
• workplace drug testing
• sports

Question 7

what kind of specimen do you get from veins post mortem + why

Answer 7

whole blood (not serum or plasma) because the blood hemolyzes

Question 8

what are 6 examples of tissues used for post mortem toxicology

Answer 8

-whole blood
-vitreous (eye)
-liver
-urine
-stomach contents
-hair
etc

Question 9

what is the main methodology for forensic tox

Answer 9

GC/MS(MS) and LC/(Q)TOF

Question 10

what are 2 main differences for instrumentation for clinical and forensic tox (so these 2 points are about forensic)

Answer 10

1-does not rely only on immunoassay

2-must use better extraction and chromatography

Question 11

is blood reliable own its own for assessing the presence of alcohol at the time of death + why

Answer 11

no because postmortem BAC can increase (from bacteria and contamination)

Question 12

what part of the body is better than blood when it comes to assessing alcohol

Answer 12

the vitreous of the eyeball

Question 13

what is the main mechanism of postmortem redistribution

Answer 13

release and diffusion from major organs

Question 14

what 2 things does postmortem redistribution dependent on

Answer 14

time and concentration dependent

Question 15

what are candidates of postmortem redistribution (2)

Answer 15

high volume of distribution (like 3L/kg)

“basic character”

Question 16

how much can concentrations increase with postmortem redistribution

Answer 16

2-10 fold

Question 17

what are the 4 orders of decreased postmortem redistribution

Answer 17

cardiac > subclavian > femoral > antemortem

Question 18

what is antemortem

Answer 18

when the sample is taken before death

Question 19

are central or more distant areas more effected by postmortem redistribution

Answer 19

central

Question 20

what is bad about postmortem redistribution

Answer 20

it can lead to mis-interpretation of toxicological results

Question 21

what are 4 main difficulties of interpreting postmortem data

Answer 21

• dont know when drug was last taken
• dont know metabolism for person
• increase and decrease conc
• dont know tolerance

Question 22

can you take a post mortem drug and then figure out the concentration

Answer 22

no, because of metabolism, tolerance… not that easy

Question 23

why is it much tricker to interpret postmortem levels of opioids

Answer 23

because there is a wide range of tolerance levels

Question 24

what is the drug that the kid died from (7 yo ADD)

Answer 24

imipramine

Question 25

how does imipramine get metabolized

Answer 25

CYP2D6 and CYP3A4

Question 26

what happens when imipramine gets metabolized by CYP2D6

Answer 26

it is metabolized again by CYP3A4 then removed by the body

Question 27

what happens when imipramine gets metabolized by CYP3A4 (Compound name + rest of pathway)

Answer 27

desipramine => it is metabolized again by CYP2D6 then removed by the body

Question 28

what is desipramine

Answer 28

when imipramine gets metabolized by CYP3A4, still active

Question 29

what happens if you are deficient in CYP2D6 and take imipramine

Answer 29

you get a build up of desipramine because it needs CYP2D6 to get excreted

Question 30

what happens if you are deficient in CYP2D6 and take codeine

Answer 30

it wont be metabolized into morphine

Question 31

what happens if you are deficient in CYP3A4 and take codeine

Answer 31

nothing, its CYP2D6 that metabolizes it

Question 32

which enzymes metabolizes codeine into morphine

Answer 32

CYP2D6

Question 33

which enzymes metabolizes imipramine into desipramine

Answer 33

CYP2D6

Question 34

what is the half life of THC in blood like

Answer 34

relatively short

Question 35

what is the half life of THC in brain like

Answer 35

longer than in blood

Question 36

what is the half life of THC in body like

Answer 36

much longer than blood and brain

Question 37

with THC, does a certain blood concentration directly correlate to impairment

Answer 37

no, not like alcohol

Question 38

what are 4 "past wisdom" things about THC that have been debunked

Answer 38

- that blood level of 2-3ng/mL means you used it within the past 6h - THC drops to near zero a few hours after last smoke - can use THC:THC-CPPH ratio to estimate time of last use - little postmortem change

Question 39

what is the typical baseline blood THC several hours after smoking in light smokers

Answer 39

often less than 2ng/mL

Question 40

what is the typical baseline blood THC several hours after smoking in heavy smokers

Answer 40

can be more than 5ng/mL

Question 41

what is the typical baseline blood THC 7 days after smoking in heavy smokers

Answer 41

1.2-5.5 ng/mL 7 days after use

Question 42

why does THC stay high in the blood

Answer 42

because THC is slowly released into the blood

Question 43

does THC go through postmortem redistribution

Answer 43

yes

Question 44

how much can THC levels in femoral blood be diff in cardiac blood with postmortem redistribution

Answer 44

it can be 6 fold higher in femoral blood than cardiac blood

Question 45

where may THC concentrate before redistributing postmortem

Answer 45

in muscle tissue

Question 46

why might you get super high levels of THC in the femoral blood post mortem

Answer 46

because there may be fat in the blood draw

Question 47

what are the 2 main things to interpret when trying to find the manner of death

Answer 47

circumstance of death and investigations (medical history, autopsy, toxicology on multiple specimens)

Question 48

what shouldnt you do if you dont have enough information

Answer 48

dont offer interpretation or give clear caveats

Question 49

what is poison hemlock

Answer 49

primary alkaloid coniine

Question 50

what are the effects of poison hemlock / coniine like

Answer 50

similar to nicotine but more toxic - paralyzes muscle by blocking nACh

Question 51

what does it look like when you die from hemlock / coniine

Answer 51

(asecnding paralysis, lower limbs affected first) respiratory paralysis leads to cessation of breathing, death from lack of oxygen

Question 52

is the hemlock tree poison

Answer 52

no

Question 53

what is the water hemlock poison

Answer 53

yes

Question 54

what is the toxin in water hemlock

Answer 54

circutoxin

Question 55

what does circutoxin do

Answer 55

disrupts CNS

Question 56

what are symptoms of circutoxin

Answer 56

nausea, emesis, abdominal pain, tremors, seizures

Question 57

what is an example of a poison nut

Answer 57

cerbera odollam

Question 58

What are the active ingredients in cerbera odollam

Answer 58

cerberin and neriifolin

Question 59

what are cerberin and neriifolin

Answer 59

potent cardiac glycosides

Question 60

what are 6 symptoms of cerberin and neriifolin overdose (cardiac glycosides)

Answer 60

nausea, vomiting, hypotension, bradycardia, heart block, arrhythmias

Question 61

what are some pretty things that can kill you

Answer 61

rosary pea seeds

Question 62

what is the toxin in rosary pea seeds

Answer 62

abrin

Question 63

what does abrin do

Answer 63

ribosome inhibiting protein