Pharm Chp 1 FC Flashcards
(39 cards)
Pharmacodynamics
study of biochemical and physiologic effects of drugs and the molecular mechanisms by which these effects are produced (drug actions and effects within the body)
Law of Mass Action
magnitude of response and rate of reaction is proportional to the number of drug-receptor complexes (efficacy of drug is altered if either changes)
Concentration at which no greater effect can be produced
Saturation (all receptors saturated)
Simple Occupancy Theory
intensity of response to a drug is proportional to # of receptors occupied by drug (max response when all receptors occupied)
Modified Occupany Theory
takes into account affinity and intrinsic activity
Strength of attraction between a drug and its receptor
Affinity (if high, drug conc can be low and drug will still bind)
Instrinsic Factor
Ability of a drug to activate a receptor following binding (reflected by max efficacy)
Mimics the body’s own regulatory molecules (endogenous ligand) and activates a receptor
Agonist (has affinity and high instrinsic activity)
Inverse Agonist
An agonist that slows down a physiologic process (due to endogenous ligand already being present in adequate amounts)
Full Agonist
Capable of produding max effect produced when drug binds receptor
Partial Agonist
Its’ max effect is lower than that of a full agonist (moderate intrinsic activity)
Produce pharmacologic effect by preventing the activation of receptors by agonists
Antagonist (has affinity but NO instrinsic activity and response determined by how much agonist is present)
Name the 3 types of Antagonists
Competetive Reversible, Competetive Irreversible and Noncompetitive
Competitive Irreversible Antagonist
Reduces # of receptors available thus reducing max response agonist can elicit (effects wear off over time as cell adds new receptors)
Noncompetitive Antagonist
Does not bind directly to agonist binding site. Reduces affinity for agonist, blocks agonist ability to cause change in receptor or coupling of receptor to signal mechanisms)
Major Types of Drug Receptors
- transmembrane ion channels, transmembrane receptors coupled to G proteins, transmembrane receptors with enzymatic cytosolic domains, intracellular receptors (enzymes and structures))
Transmembrane Ion Channels
Allows passage of hydrophilic ions across the plasma membrane (produce AP in cardiac and skeletal muscle)
Drugs may affect the function of these ion channels by directly opening or closing the channel
Ligand gated ion channels
How many types of transmembrane ions channels are there?
- Ligand gated, voltage gated and second messenger gated
Most abundant call of receptors
G protein coupled receptors
Major role of G protein coupled receptors
to activate second messengers
Largest group of receptors with enzymatic cytosolic domains
tyrosine kinase family
Tyrosine kinase
modifies proteins by phosphorylation (adding or removing a phosphate group)
Which type of drug receptors affect transcription?
Intracellular receptors (either increase or decrease transcription of RNA)