Pharm- toxcology

Question 1

define toxicology

Answer 1

the study and science of poisons (toxicants), their physical and chemical properties, sources, biological effect, mechanism of action, clinical signs, lesions, analysis, diagnosis and treatment (or prevention) of diseases caused by toxicants

Question 2

define toxicant

Answer 2

also called a poison
any substance (solid, liquid or gas) when applied or introduced into the body may interfere with life processes or biological functions of the cells of the animal

Question 3

what are 3 forms of exposure, 3 forms of diagnosis, 3 forms of treatment, and 2 forms of prognosis for for toxicology

Answer 3

exposure: species susceptibility, species sensitivity, sources of toxicity
diagnosis: clinical findings, lab findings, specific lesions
treatment: decontamination, specific antidote, organs affected
prognosis: risk to other animals, risk to people or public health

Question 4

what are the 4 aspects of toxicokinetics?

Answer 4

mechanism of action
metabolism
excretion
half-life

Question 5

what is the difference between poisons and drugs?

Answer 5

dose

Question 6

define xenobiotics

Answer 6

drugs & poisons

foreign chemicals that the body does not produce

Question 7

what 2 things are the toxicologist and the clinician interested in?

Answer 7

drug toxicity

toxicity due to other chemicals

Question 8

define biotoxin

Answer 8

poison from a biological process

Question 9

define toxic

Answer 9

the deleterious or undesirable effects of a poison

Question 10

define toxicosis

Answer 10

disease caused by exposure to a toxin

Question 11

define toxicity

Answer 11

the amount of poison that under certain circumstances will cause a toxicity

Question 12

how is toxicity expressed in mammals?

Answer 12

Ld50

in mg/kg body weight

Question 13

how is toxicity expressed in birds and fish?

Answer 13

birds: LC50 in mg/kg feed
fish: LC50 in mg/L water

Question 14

what are the 4 types of toxicity and define them

Answer 14

acute: the effect of a single dose or multiple doses over 24 hours
subacute: effect produced by daily exposure from 1-30 days
subchronic: effect exposed from daily exposure from 30-90 days
chronic: effect produced by daily exposure from 3+ months

Question 15

what are the 8 factors that influence toxicity of a substance?

Answer 15

species
breed
individual
sex
age
dosage of poison
duration of exposure
idiosyncrasies

Question 16

what is chronicity factor?

Answer 16

ration between acute LD50 and chronic LD50

Question 17

what two aspects will lover chronicity factor, what will increase it and what does the factor >2 indicate?

Answer 17

rabidly metabolized compounds & development of tolerance due to inc metabolism = low factor
compounds with a cumulative effect= high factor
>2 indicates relatively cumulative toxin

Question 18

define the highest nontoxic dose

Answer 18

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

Question 19

define maximum tolerated dose or minimal toxic dose

Answer 19

similar to highest nontoxic dose

Question 20

define toxic dose flow

Answer 20

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

Question 21

define toxic dose high

Answer 21

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

Question 22

define no effect level (maximum nontoxic level)

Answer 22

the amount of a chemical that can be ingested without causing any deaths, illness or toxic alterations in any animal for the stated period (usually 90 days - 2 years)

Question 23

define lethal dose, what kind of response is it?

Answer 23

dose that causes death in any animal during a period of observation
all or non response (alive vs not alive)

Question 24

what does lethal dose not give information about?

Answer 24

severity of clinical signs, chronicity or relationship to other effects such as reproductive abnormalities and ability to cause cancer

Question 25

what are lethal doses set in?

Answer 25

confined conditions such as species, route of administration and duration of exposure

Question 26

when is LD50 typically used?

Answer 26

toxicant studies

Question 27

What is LD0, LD50, LD100?

Answer 27

LD0= highest dose that does not cause any death
LD50= medial lethal dose that kills 50% of animals in a group
LD100= lowest dose that kills all the animals in a group

Question 28

what is hazard and how is the risk factor calculated?

Answer 28

hazard is the danger from possibility of exposure

the risk factor is calculated as the ration between toxicity and use level