9.23 Pharmacodynamics Flashcards
drugs that block access of an agonist to its receptor. They do not change the receptor conformation or have any transduction.
antagonist
does an antagonist have potency?
yes, measure against agonist. if you need less to produce effect, more potent
if there are spare receptors for a drug, ____ will be less than ____.
ED50 < Kd
G__ acts to inhibit AC, decreasing cAMP levels and deactivating PKA
I
kinase receptors usually ____ and cross-________
dimerize, cross-phosphorylate
G__ is stimulatory, G__ is inhibitory, G__ acts on PLC
S
I
Q
dosage (concentration) required to induce (or block if negative) a response. amount of drug required to bring around a response. ability to get to site of action, etc.
potency
additional G proteins can activate ______, which causes release of arachidonic acid from the plasma membrane
PLA2
the therapeutic index is between the ____________ curve and the _________ curve
therapeutic effect curve
lethal dose curve
A G-protein can alter ion channel activity by the ____ subunit indirectly gating ion channels from the intracellular side
beta-gamma
ability of a drug to induce a response by itself
efficacy
Taking the chemical message and turning it into a biochemical event within the cell.
signal transduction
A graph of the fraction of a population that shows a specified response (either produced or not produced) at progressively increasing doses.
quantal dose-response curves
Interacts with receptor at recognition site but cannot produce a maximum response (reduced efficacy).
partial agonist
A graph of increasing response to increasing drug concentration or dose
graded dose response curve
the therapeutic window is between the ______________ curve, and the ______________ curve
therapeutic effect curve
side effect curve
equation for therapeutic window:
TW = TD50/ED50
TD - toxic dose
ED - effective dose
an agonist has _____ efficacy. A partial agonist has _____ efficacy. An antagonist has _____ efficacy
high
reduced
no
in dose response curves, potency is associated with _______ shift, and efficacy is associated with _______ shift
Left/right
up/down
antagonists that interact irreversibly with the receptor recognition site, usually by formation of covalent bond. Agonists can’t compete and overcome blocking action.
noncompetitive antagonist
____ receptors can imitate a chain reaction of protein phosphorylation
kinase
competitive agonists decrease ______, while noncompetitive agonists decrease _______ and or ______
potency
potency, efficacy
The concentration of drug that binds 50% of the receptors in the system (total receptors in the system - if this was bound, it would be Emax)
Kd
in the Gq pathway, DAG activates _____ and IP3 activates ____, letting Ca++ into the cell from ER, activating _____
PKC
IP3R, CAMk
G__ acts on AC, increasing cAMP levels and activating PKA
S
the dose on a dose response curve that produces half of the maximal response
ED50
G__ acts on PLC, which acts on _____, releasing into two components (____ and ____)
Q
PIP3
IP3 and DAG
equation for therapeutic index:
TI = LD50/ED50
LD = lethal dose
binds in the same spot on the receptor as the drug, blocking binding of agonist. Can be overcome by increasing drug concentration.
competitive agonist
define: drugs that interact with specific receptors and cause a change in conformation of the receptor, transduction, and amplification. Full efficacy
agonist
low Kd = _____ affinity
high
what are the three main forces between drugs and their receptors?
ionic bonds, H bonds, van der Waals forces
a partial agonist can behave as a partial ________ in the presence of a full agonist. This _____ efficacy.
antagonist
decreases
what are the three components of a drug receptor system?
- recognition site
- transducer mechanism
- amplification system
the higher the therapeutic index, the ______ the drug
safer
In graded dose-response curves, the concentration or dose that causes 50% of the maximal effect. In quantal dose-response curves, the concentration or dose that causes a specified response in 50% of the population under study
ED50/EC50
