Pharm- toxcology Flashcards
define toxicology
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
define toxicant
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
what are 3 forms of exposure, 3 forms of diagnosis, 3 forms of treatment, and 2 forms of prognosis for for toxicology
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
what are the 4 aspects of toxicokinetics?
mechanism of action
metabolism
excretion
half-life
what is the difference between poisons and drugs?
dose
define xenobiotics
drugs & poisons
foreign chemicals that the body does not produce
what 2 things are the toxicologist and the clinician interested in?
drug toxicity
toxicity due to other chemicals
define biotoxin
poison from a biological process
define toxic
the deleterious or undesirable effects of a poison
define toxicosis
disease caused by exposure to a toxin
define toxicity
the amount of poison that under certain circumstances will cause a toxicity
how is toxicity expressed in mammals?
Ld50
in mg/kg body weight
how is toxicity expressed in birds and fish?
birds: LC50 in mg/kg feed
fish: LC50 in mg/L water
what are the 4 types of toxicity and define them
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
what are the 8 factors that influence toxicity of a substance?
species breed individual sex age dosage of poison duration of exposure idiosyncrasies
what is chronicity factor?
ration between acute LD50 and chronic LD50
what two aspects will lover chronicity factor, what will increase it and what does the factor >2 indicate?
rabidly metabolized compounds & development of tolerance due to inc metabolism = low factor
compounds with a cumulative effect= high factor
>2 indicates relatively cumulative toxin
define the highest nontoxic dose
the highest or largest dose which does not result in undesirable or toxic alterations
define maximum tolerated dose or minimal toxic dose
similar to highest nontoxic dose
define toxic dose flow
the lowest dose which produces toxic alterations and administering twice this dose will not cause death
define toxic dose high
the dose which produces toxic alterations and administering twice this dose will result in death
define no effect level (maximum nontoxic level)
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)
define lethal dose, what kind of response is it?
dose that causes death in any animal during a period of observation
all or non response (alive vs not alive)
what does lethal dose not give information about?
severity of clinical signs, chronicity or relationship to other effects such as reproductive abnormalities and ability to cause cancer
what are lethal doses set in?
confined conditions such as species, route of administration and duration of exposure
when is LD50 typically used?
toxicant studies
What is LD0, LD50, LD100?
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
what is hazard and how is the risk factor calculated?
hazard is the danger from possibility of exposure
the risk factor is calculated as the ration between toxicity and use level