Misty Lecture Flashcards
Toxicology
the study of adverse effects of chemical and other agents on living organisms and ecosystems
Toxicity
ability of a material to damage biological systems, cause injury of impair function
hazard
ability of an agent to acuse toxicity
risk
the expected frequency of exposure to a hazardous agent
route of exposure
route of entry onto the body. inhalation, transdermal, mucousal
duration of exposure
may affect selection of treatment.
Acute vs Chronic
ADME
Absorption, distribution, metabolism, excretion
clearance
measure of plasma cleared per unit time
sum of both hepatic and renal contributions
1st order kinetics
elimination of most drugs is proportional to their plasma concentration
Zero order kinetics
plasma levels become very high– protein binding and normal metabolism can both become saturated and the rate of elimination can become fixed.
not dependent on plasma concentration
more drug is delivered into circulation in inbound fraction- easier to become toxic.
Volume of distribution
apparent volume into which a substance is distributed in the body
large Vd
substance will not be easily accessible to purification attempts
antidepressants, antipsychotics, antimalarials, opiods
HARDER TO REMOVE
Small Vd
better candidates
salicilates, ethanol, phenobarbital
bioaccumulation
accumulation of toxic agent when the uptake exceeds the organism’s ability to metabolize/excrete it
biomagnification
increases in the relative amount of a contaminant in a biological system as it passes up the food chain
mercury increases up the food chain
biocompatability
material’s ability to perform with an appropriate host response
Lead
burtonian lines- lead lines causing a darkening of the gingiva
TREAT with EDTA, removes from bone slowly.
it is absorbed more in children because it competes with Ca++
t1/2- 1-2 months
Mercury
reacts with selenium
Gingivostomatitis, neurological, and psychiatric sympts.
MAD HATTER- memory loss, depression, confusion
TREAT with Dimercaprol
and succimer
Arsenic
absorbed via respiratory and GI
hyperpigmentation, anemia, kidney failure
carcinogenic in lungs, skin and bladder.
Hemolytic
Acute arsenic intox
decontaminate
unithol IV
Dimercaprol IM
Chronic arsenic intoxication
folate dietary supplement
NO CHELATORS
irreversible damage has already occured.
acute arsine gas
hemodialisis and transfusions
aggressive hydration
NO CHELATORS
Chelators
they chelate ions so that they cant interact with other things.
the longer
