Exam 1 Flashcards
dose
amount to which an individual was exposed
dosage
amount of substance that produces an effect in a population
toxicity
amount of substance that produces an adverse effect in a population
toxin vs toxicant
from living organisms vs human-made
hormesis
providing benefits at low levels of exposure, but adverse effects at higher levels
graded dose-response curve
individual response to an agent vs dose, sigmoid curve
quantal dose-response curve
agent response vs dose for a population, looks more like a standard deviation plot
therapeutic index
LD50 / ED50
6 limitations of dose-response curves
only from acute exposures, not account for environment or other agents, interspecies differences, toxin form, diet, route of exposure
sweat pore percutaneous absorption
lipid soluble agents in sebaceous glands
what limits higher and lower blood gas partition coefficients
ventilation and perfusion respectively
phase I vs phase II metabolism reactions
phase I: oxidation, reduction, hydrolysis to change molecule (increase polarity?)
phase II: conjugation reactions couple toxic agents to other molecules (most likely to lose toxicity)
three major enzymes that can be induced (microsomal)
cytochrome P450s (I) and glucuronidation, glutathione concentration (II)
P450 inducers (6)
rifampin, phenobarb, glucocorticoids, tobacco, chronic ethanol, fipronil
P450 inhibitors
ketoconazole, macrolides, a-napthoflavone, aminotriazole
fipronil (frontline) increases toxicity of specifically which drug
acetaminophen
gene for enzymes that metabolism acetaminophen in cats
UGT1A6
enzymes dogs lack that may contribute to sulfonamide toxicity
NAT1 and NAT2
gene for enzymes that metabolism propofol in cats
UGT1A9
zero order vs first order elimination
constant rate (or saturated system), proportion eliminated at a time
solid 1% =
10 mg/g
liquid 1% =
10 mg/mL
1ppm =
1 mg/kg = 1 microg/g
1 g/ton =
1 g / 909 kg
