Toxicology

Question 1

most common route of occupational exposure

Answer 1

inhalation

Question 2

most common route of exposure in poisonings

Answer 2

ingestion

Question 3

Acute poisoning - think more…

Answer 3

cell death

Question 4

chronic poisoning - think more…

Answer 4

chronic inflammation/wounding

cell proliferation

Question 5

Linear model

dose-response curve

Answer 5

NO SAFE EXPOSURE!

ex. DNA damage

Question 6

Threshold model

dose-response curve

Answer 6

Safe level = below threshold

Threshold = toxic S.E./Death

Question 7

Hormetic Model

dose-response curve

Answer 7

Low levels = protective

Past threshold = toxic

Question 8

Drug interaction risk factors

Answer 8

Age
Polypharmacy
Impaired elimination
narrow T.I.

Question 9

Toxicity MOAs

Answer 9

• Receptor-ligand
• Membrane function change
• Block ATP formation
• Macromolecule interaction (protein, lipid, DNA = DAMAGE)
• Change Ca+ balance
• Free radicals

Question 10

Benzene - DNA damage path

Answer 10

Phase 1 minor pathway

MPO–> 1,4 Benzequinone

Question 11

acetaminophen - Hepatocyte death pathway

Answer 11

phase 1

Question 12

produce proxidants?

Answer 12

• p450 metab in mitochondria

* reperfusion injury

Question 13

Glutathione

Answer 13

antioxidant, gives electron/H (phase 2)

Question 14

Paraquat

Answer 14

Herbicide

*pulm fibrosis (OH free radical)

Question 15

Parathione

Answer 15

Organophosphate/Carbamate insecticide

• AchE enzyme inhibition (pulm)
• ANTIDOTE = Atropine Sulfate (anti-musc)

Question 16

Methemoglobin

Answer 16

Hb Fe3+

• Nitrate exposure
• Methelyne blue (+methemoglobin reductase)

Question 17

Cyanide

Answer 17

*block aerobic metab (cytochrome oxidase)
*ANTIDOTE =
1)amyl/sodium nitrate
(CN binds to Fe+++)
2)Hydroxycobalamin
(CN binds –> b12)
3) Sodium Thiosulfate

Question 18

Arsenic

ground water

Answer 18

PV disease (black foot)

skin cancer

Question 19

Cadmium

ground water

Answer 19

osteomalacia

Teste damage

Question 20

Treatment for metal poisioning?

Answer 20

Succimer
(Dimercaptosuccinic Acid/DMSA)
-for lead/mercury
-only for Rx in PLASMA

Question 21

Chelation sometimes can’t block completely

Answer 21

• Stable complex = complete

* Basket complex = incomplete

Question 22

Mercury

Answer 22

CNS toxicant
Methylmercury/dimethyl
   *organic
   *lethal (Dr. Wetterhahn)
    *SH groups/selenium

Question 23

Lead

Answer 23

CNS effects
mimics Ca/zinc = 
Vit D synth
Heme synth
Detect = Venous level