Introduction

Question 1

what is toxiology

Answer 1

science of poisons (toxicants)

Question 2

toxicology can be defined as

Answer 2

the science of toxicants, their physical and chemica properties, sources, biologic effects, mechanisms of action, clinical signs, lesions, analysis, diagnosis, differential diagonosis and treatment(or prevention) of diseases caused by toxicants

Question 3

main aspects of clinical toxicology

Answer 3

diagnosis

treatment

Question 4

T/F drugs can be poisons and poisons can be drugs

Answer 4

True

the dose is the difference

Question 5

drugs and poisons are both

Answer 5

xenobiotics

foreign chemicals that the body does not produce

Question 6

poison (toxicant)

Answer 6

any substance (solid, liquid, or gas) when applied or introduced into the body may interfere with life processes or biological functions

Question 7

sources of poisons

Answer 7

natural (plant, animal, mineral, fungi or bacteria)

synthetic (organophostphates, insecticides, herbicides etc)

Question 8

toxin (biotoxin)

Answer 8

poison from a biologic process

e.g. zootoxins or animal toxins, phytotoxins or plant toxins, bacterial toxins and mycotoxins

Question 9

toxic

Answer 9

used to describe the deleterious or undesireable effects or poisons

Question 10

toxicosis (poisoning or intoxication)

Answer 10

disease caused by exposure to a poison

Question 11

toxicity

Answer 11

amount of a poison that under certain circumstances will cause toxic effects

Question 12

toxicity is usually expressed as

Answer 12

mammals: LD50 in mg/kg of body weight

birds: LC50 (lethal concentration 50) in mg/kg feed

fish: LC50 in mg/liter water

Question 13

acute toxicity

Answer 13

effect of single or multiple doses during a 24 hour period

Question 14

subacute toxicity

Answer 14

effect prodiced by daily exposure from 1-30 days

Question 15

subchronic toxicity

Answer 15

effect of exposure from 30-90 days

Question 16

chronic toxicity

Answer 16

effect produced by daily exposure for a period of 3 months or more

Question 17

chronicity factor

Answer 17

ratio between acute LD50 and chronic LD50

ex: warfarin: acute LD50 = 1.6, chronic LD50 = 0.077
1. 6/0.077 = 21.0

Question 18

T/F counpounds with cumulative effect have a high chronicity factor

Answer 18

True

chronicity factor >2.0 indicates a relatively cumulative toxicant

Question 19

toxicity values are influenced by

Answer 19

species, breed, individual, sex, age, dosage of poison, duration of exposure, and other factors

Question 20

extremely toxic

Answer 20

1 mg/kg or less

Question 21

highly toxic

Answer 21

>1-50 mg/kg

Question 22

moderately toxic

Answer 22

> 50-500 mg/kg

Question 23

slightly toxic

Answer 23

0.5-5 g/kg

Question 24

practically nontoxic

Answer 24

>5-15 g/kg

Question 25

relatively harmless

Answer 25

> 15 g/kg

Question 26

highest nontoxic dose (HNTD)

Answer 26

highest or largest dose which does not result in undesirable or toxic alterations

Question 27

maximum tolerated dose or minimal toxic dose (MTD)

Answer 27

similar to the highest nontoxic dose

Question 28

toxic dose low (TDL)

Answer 28

lowest dose which prodices toxic alterations and administering twice this dose will not cause death

Question 29

toxic dose high (TDH)

Answer 29

dose which produces toxic alterations and administering twice this dose will result in death

Question 30

no-effect level (maximum nontoxic level)

Answer 30

amount of a chemical that can be ingested without causing any deaths, illness or toxic alterations in any of the animals for the stated period (usually 90 days to 2+ years depending on species)

Question 31

lethal dose

Answer 31

dose that causes death in any animal during the peroid of observation

Question 32

LD0

Answer 32

highest does that does not cause any death

Question 33

LD50

Answer 33

the dose that kills 50% of animals in the group

Question 34

LD 100

Answer 34

loest dose that kills all the animals in the group

Question 35

hazard

Answer 35

danger from the possibility of exposure

Question 36

T/F a poison may be highly toxic but not hazardous

Answer 36

True

Question 37

risk ratio

Answer 37

calculated as the ratio between toxicity and use level

ex. urea: toxicity = 300mg/kg, use level = 100mg/kg; risk ratio= 3:1
monensin: toxicity = 20mg/kg, use level = 1mg/kg; risk ratio= 20:1

monensin is much more toxic than urea but the risk of urea toxicosis is much higher than monensin toxicosis