Introduction to drug action Flashcards
(19 cards)
What is pharmacology?
The study of drugs, how they work, what they are and what they do
What is pharmacodynamics?
What a drug does to the body - the biological effects and mechanisms of action
What is pharmacokinetics?
What the body does to a drug - absorption, distribution, metabolism, excretion of drugs and their metabolites
What is a medicine?
A chemical preparation containing one or more drugs used with the intention of a therapeutic effect. For a drug to be useful, it must act selectively
How do drugs act?
Drugs act by binding specifically to target molecules - receptor and ligand lock and key theory
What are regulatory proteins that drugs bind to?
Enzymes Carrier molecules (transporters and pumps Ion channels Receptors RNA DNA
What is an agonist?
A drug that binds to a receptor to produce a cellular response
What is an antagonist?
A drug that blocks the action of an agonist bu binding to the same receptor
What two features do agonists have?
Affinity and Efficacy
What determines affinity?
The chemical bonds between a ligand and its receptor
What is efficacy?
The ability of an agonist to evoke a cellular response
What 2 features do antagonists have?
Affinity but lack efficacy
What is the relationship between concentration and response on a linear plot?
Hyperbolic
What is EC50?
The concentration of agonist that elicits a half maximal response
What is the relationship between concentration and response on a semi-logarithmic plot?
Sigmoidal
What is competitive antagonism?
The binding of an agonist and antagonist occur at the same (orthosteric) site and is thus competitive and mutually exclusive
What is non-competitive antagonism?
The agonist binds to the orthosteric site and the antagonist binds to a separate allosteric site and is thus non competitive
What effect does competitive antagonist have on a graph of response against concentration?
Parallel rightward shift of the agonist concentration response curve with no depression of the maximal response
What effect does non-
competitive antagonist have on a graph of response against concentration?
Depresses the slope and maximum of the concentration response curve but does not cause a rightward shift
