Exam 1: Dynamics Flashcards
Pharmacodynamics
study of physiological and biochemical interaction of drug molecules with target tissue that is responsible for ultimate effects of drug
Large protein molecules located on cell surface/within cells that are initial sites of action of biological active agents
receptor
Two types of receptors
cell surface-extracellular
Intracellular: cytoplasm/nucleus
Most hormones that acat on brain to influence neural events use ___ receptor
intracellular
high affinity
attach most readily
low effiacy
can attach, but doesn’t do anything
antagonist
block effect
agonist
act as NT
Partial agonists
efficacy less than full agonists, but more than antagonist
-effect, but not as much
Technically some intrinsic activity
Inverse agonists
initiate biological action, but action is opposite to agonist
Receptor number modification
long term regulation:
up-regulation: increase receptors
down regulation: decrease receptors
Receptors modified in sensitivity
more rapid regulation via 2nd messengers
The idea that receptor proteins have different characteristics in different target tissue
receptor subtypes
Does response curve
describes the extent of biological/behavioral effect (mean response in population) produced by given [drug]
ED50
dose that produces 1/2 maximal effect
ED100
maximum response occurs at does which we assume receptors fully occupied
Potency
absolute amount of drug necessary to produce a specific effect
maximum on y-axis
efficacy
TD50
does at which 50% of the population experiences a particular toxic effect
Therapeutic index
TI= TD50 / ED50
LD50 / ED 50
Factor index
dose of drug that is lethal to 1% of the population compared with the dose that is therapeutically effective in 99% of the population (LD1 / ED99)
Competitive Antagonists
can be displaced from sites by excess of agonist because increase [drug] competes more effectively for fixed receptors
Noncompetitive antagonists
drugs that reduce effects of agonists in ways other than competing for the receptor.
e.i. binding to portion of receptor other than agonist binding site
Physiological antagonism
two drugs that act in 2 distinct ways but interact in such a way that they reduce each other’s effectiveness in the body
Potentiation
situation in which combo of 2 drugs produces effects that are greater than the sum of their individual effects.
Radioligand binding
used to study number of receptors in given region
Radioligand: to measure amount of ligand that binds to sites we are concerned with, add
very high [nonradioactive competing ligand] to some tubes to show most radioactive binding displaced.
radioligand: ___ binding subtracted when data for specific binding calculated
nonspecific
Saturability
finite # receptors in tissue.
Point at which binding curve plateus
Bmax
If you compare rate of dissociation with rate of binding, you get ___
Kd
Kd
dissociation constant, measure of drug affinity for specific receptor