29: Forensic Toxicology

Question 1

clinical tox testing is only done if

Answer 1

it is likely to influence tx fo pt

Question 2

TDM has a limited menu of drugs such as

Answer 2

immunosuppressants and some anticonvulsants

Question 3

clinical tox usually tests

Answer 3

serum or plasma

Question 4

the medical examiner system may be lead by

Answer 4

a forensic pathologist

Question 5

the coroner system may

Answer 5

or may not be headed by a phyusician

Question 6

what is the “cause” of death

Answer 6

immediate medical cause of death, not the circumstances of death (i..e blunt force trauma, and not the MVA)

Question 7

what is the “manner” of death? what are the 6 “manners” of deaht?

Answer 7

specific categories like accident (44%), natural (40%), suicide (14%), undetermined (2%), homicide (1.5%), unclassified (MAID deaths)

Question 8

T or F: time of death is usually not possible to determine

Answer 8

T

Question 9

what is the most common manner of death

Answer 9

accident

Question 10

postmortem toxicology uses specimens other than serum or plasma such as

Answer 10

whole blood, vitreous, urine (workplace testing, saliva/ oral fluid), liver, stomach contents, other tissues (sometimes b/c decomp), hair (sometimes for criminal cases)
Bile, CSF, virtually any fluid
Lungs, kidney, muscle, or any solid tissue
Bone, nails, hair

Question 11

what is the principle of using specimens other than plasma or serum in postmortum toxicology

Answer 11

most drugs are distributed to virtually all fluids and tissue in the body

Question 12

what is the main difference between postmortem and clinical toxicology

Answer 12

postmortem tox must consider all aspects of death. postmortem has to think about CONTEXT of death, and INTERPRETATION of samples is more difficult.

Question 13

why are medication counts important in forensic tox

Answer 13

in order to determine if death was due to build up or suicide

Question 14

deaths due to impaired metabolism may be due to (3)

Answer 14

Genetic impairment due to enzyme deficiency
Drug drug impairment of enzyme system
Impairment due to reduced liver function (age, alcohol)

Question 15

imipramine’s metabolite is _____________, which can accumulate if the patient has a _______ deficiency

Answer 15

desipramine
2D6

Question 16

___________ decreases metabolism of desipramine

Answer 16

chlorpromazine

Question 17

3 main mechs of postmortem redistribution

Answer 17

Release and diffusion of drugs from major structures
Occurs as cells die, pH changes, and protein binding weakens
Time and concentration dependent

Question 18

what are 2 characteristics of candidate drugs for post mortem redistribution

Answer 18

Drugs with high volume of distribution typically >5L/kg
Drugs with “basic” character (ex- from HCL salts)

Question 19

postmortum distribution increases ____x drug concentrations

Answer 19

2-10

Question 20

list the order of increasing magnitude of PM redistribution in the 3 major blood vessels: subclavian, cardiac, femoral

Answer 20

cardiac > subclavian >femoral

Question 21

in interpreting postmortem narcotic blood levels, we need to know

Answer 21

the degree of tolerance

Question 22

if the postmortem exam is done on an opioid naive person, interpretation is _______

Answer 22

easier

Question 23

what is the reference chloroform concentration for homicide

Answer 23

10-49mg/L

Question 24

what is the reference chloroform conc for suicide

Answer 24

17-43mg/L

Question 25

what is the reference chloroform conc for anesthesia

Answer 25

50-150mg/L

Question 26

chloroform concs for homicide and suicide may be lower due to

Answer 26

asphyxiation death