Principles of Toxicology Flashcards Preview

Toxicology > Principles of Toxicology > Flashcards

Flashcards in Principles of Toxicology Deck (32):
1

Father of Toxicology

Paracelsus- Swiss physician

2

toxic

something poisonous, or causes adverse effects

3

toxicology

the study of poisons

concerned with identification, treatment and assessing risks of poisons

4

toxicant

compounds that cause toxicity

may be natural or man-made xenobiotic

5

xenobiotic

foreign substance

6

antidote

  • remedy to counteract poison
  • usually refers to any substance that prevents/relieves the effects of a toxicant
  • no antidote works on all toxins and some can be potentially harmful

7

toxins

consist of manmade chemicals and natural products

8

classify as extremely toxic

< 1 mg/kg

ex: botulism, strychnine

9

classify as highly toxic

1-50 mg/kg

ex: nicotine

10

classify as moderately toxic

50-500 mg/kg

ex: aspirin, foxglove, acetaminophin

11

classify as slightly toxic

0.5-5 g/kg

ex: salt, grapes

12

classify as practically non-toxic

5-15 g/kg

13

classify as relatively harmless

> 15 g/kg

ex: water

14

additive chemical interaction

sum of the effects

1 + 1 = 2

15

antagonistic chemical interactions

blocks or brings down the negativity of the effects

1 + 1 = 1

16

synergistic chemical interaction

compounds work together and significantly increase the effects

1 + 1 = 4

17

factors related to the toxicant

  • chemical structure
  • affinity for some molecules
  • what the toxicant is mixed in (carrier, adjuvant)

18

factors related to exposure

  • dose 
  • route of entry
  • duration of exposure

19

factors related to the subject

  • species
  • age of animal (young and old more susceptible)
  • health status
  • prior exposure
  • physiological complications

20

factors related to the environment

  • climate/temperature
    • chemicals degrade faster at higher temperatures, body temp dictates how drugs are metabolized
  • pH of stomach 
    • affects absorption of chemicals

21

examples of species differences

  • cats deficient in glucuronidation
  • dogs deficient in acetylation
  • pigs deficient in sulfation
  • pregnancy also alters metabolism

22

acute exposure

single dose exposure or several doses within a 24 hour period

23

sub-acute/subchronic exposure

exposure over 7-90 days

24

chronic exposure

protracted exposure (6 months -  lifetime)

25

dose-response relationship

  • central concept of toxicology
  • assumes a cause and effect relationship and that response is proportional to dose

26

4 concepts important to toxicokinetics

  • Absorption
  • Distribution
  • Excretion
  • Metabolism

27

most important veterinary toxicants are absorbed via which routes?

oral and dermal

28

job of metabolism

detoxifies a compound and increases its elimination

29

bioactivation

  • when metabolism increases the toxicity of a compound
  • ex: benzoapyrene, aflatoxin, acetaminophen
  • also happens with some drugs

30

4 steps in the mechanism of toxicity 

  1. delivery from site of exposure to target
  2. reaction of the ultimate toxicant with the target molecule
  3. cellular dysfunction and resultant toxicities
  4. repair (apoptosis, tissue regeneration) or disrepair (tissue necrosis, fibrosis, cancer)

31

2 main ways toxicants cause toxicity

  1. cellular damage (can result from free radical damage, inhibition of energy production, disruption of enzyme function)
  2. organ system dysfunction (not associated with specific cellular injury, but lethal to intact organism)

32

10 of the most dangerous foods for dogs

  1. alcohol
  2. avocados
  3. chocolate
  4. coffee and caffeine
  5. fruit with pits and seeds
  6. grapes and raisins
  7. macadamia nuts
  8. garlic and onions
  9. xylitol
  10. yeast dough