Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
30 Cards in this Set
- Front
- Back
|
How is most drug action mediated?
|
Through a receptor
|
|
|
What are the modern concepts of drug-receptor interactions?
|
fundamental principle of drug action, won't create a new cell or new fcn, creates a cascade of events-> amp signal, may involve 2nd messengers
|
|
|
What are receptors?
|
A cellular component (nucleic acid, lipids in membrane, polysacch, glycopro, proteins, located on cell surface, inside membrane, or intracellular
|
|
|
What type of rxn is drug-receptor interactions?
|
chem rxn
|
|
|
What is the physical chemical relationship based on?
|
molec size & distances and degree of positive or neg charge
|
|
|
What are the charac of drug-receptor interactions?
|
Chemical bond holds drug in place for a min period of time (covalent, ionic, hydrogen, Van der Waals)
|
|
|
What determines the length of time the drug & receptor are in contact?
|
The type of bond
|
|
|
How does the 3D structure of the drug play a role in its interaction w/ receptor?
|
The more closely the 3D structure assumes proper fit the more important the weaker bond types become
|
|
|
What equation explains the relationship b/w dose & effect?
|
Change = (max change)(D)/(D)+(Kd), where Kd =K2/K1 & D= concen of drug @ receptor site (Michaelis-Menton: Law of mass action).
|
|
|
Describe a dose-response curve.
|
x-axis is dose in log scale. Y-axis is % max response. Sigmoid curve. Kd = dose @ 50% max response
|
|
|
Why is the log scale used in dose-response curve?
|
creates a linear curve in the area of max change
|
|
|
What info is obtained in from graded dose-response curve?
|
Potency, efficacy, & intrinsic activity
|
|
|
What is potency?
|
How much drug is needed. Position rt to lt on the dose-response curve
|
|
|
What is efficacy?
|
The magnitude of the response; the height of the y-axis
|
|
|
What is intrinsic activity?
|
Used synonymous w/ efficacy
|
|
|
What are quantal dose-response curves?
|
Not all effects are graded so it relate dose to the % of subjects in a pop showing a given response
|
|
|
How can you tell the diff b/w graded & quantal-dose response curves?
|
Y-axis is % max response on graded curve & % pop on quantal curve
|
|
|
What info is gained in quantal dose-response curve?
|
Potency (ED50 & LD50), Variability of response (slope), therapuetic index (measures safety), comparing tails allows for a more conservative safety estim, & Certain Safety Factor
|
|
|
What is therapuetic index?
|
LD50/ED50. Valid if slopes parallel. For small # more care is needed when determining dose
|
|
|
What is Certain Safety Factor?
|
Considers the tails of the curve whether parallel or not. TD1/ED99
|
|
|
What are agonists?
|
Drugs that produce max or near max effect when they interact w/ a receptor
|
|
|
What are antagonists?
|
Drugs which produce no effect of their own but block the actions of endogenous substances or exogenous admin drugs
|
|
|
What are partial agonists?
|
Drugs which bind to the receptor but even w/ full receptor occupancy, they are not capable of producing the max effect seen in true agonist. Can block affects of true agonist when co-admin
|
|
|
What are inverse agonists?
|
Drugs that bind the receptor & produce an effect opposite to that of the agonist when @ same receptor
|
|
|
What are the 3 types of antagonism?
|
Chemical, Functional/Physiological, & Pharm
|
|
|
What is Chemical antag?
|
Simple chem rxn b/w 2 cmpds w/o receptor->inactive cmpx or new cmpd w/ diff activity or none @ all
|
|
|
What is Physiological antag?
|
The result of 2 agonists w/ opposite pharm activites
|
|
|
What are the 2 types of pharm antag?
|
Competitive & non-competitive (both same receptor)
|
|
|
Describe Competitive antag.
|
Antag blocks action of agonist @ same receptor, can be overcome by adding more agonist, shifts ED50 rt (potency), no change in efficacy (max response)
|
|
|
Describe Non-compet antag.
|
Antag blocks actions of agonist by interacting w/ receptor, can't be overcome, ED50 doesn't change, efficacy (max response) dec
|
