Flashcards in 9.23 Pharmacodynamics Deck (36):
drugs that block access of an agonist to its receptor. They do not change the receptor conformation or have any transduction.
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
kinase receptors usually ____ and cross-________
G__ is stimulatory, G__ is inhibitory, G__ acts on PLC
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.
additional G proteins can activate ______, which causes release of arachidonic acid from the plasma membrane
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
ability of a drug to induce a response by itself
Taking the chemical message and turning it into a biochemical event within the cell.
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).
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
in dose response curves, potency is associated with _______ shift, and efficacy is associated with _______ shift
antagonists that interact irreversibly with the receptor recognition site, usually by formation of covalent bond. Agonists can’t compete and overcome blocking action.
____ receptors can imitate a chain reaction of protein phosphorylation
competitive agonists decrease ______, while noncompetitive agonists decrease _______ and or ______
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)
in the Gq pathway, DAG activates _____ and IP3 activates ____, letting Ca++ into the cell from ER, activating _____
G__ acts on AC, increasing cAMP levels and activating PKA
the dose on a dose response curve that produces half of the maximal response
G__ acts on PLC, which acts on _____, releasing into two components (____ and ____)
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.
define: drugs that interact with specific receptors and cause a change in conformation of the receptor, transduction, and amplification. Full efficacy
low Kd = _____ affinity
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.
what are the three components of a drug receptor system?
1. recognition site
2. transducer mechanism
3. amplification system
the higher the therapeutic index, the ______ the drug