1.
• Is essentially insurmountable
• It is essentially irreversible
• And at high concentrations of the antagonist, a depression of the maximum is observed: Non-competitive antagonism (irreversible competitive)
2.
• Surmountable and reversible: there is no depression of the maximum response.
• There are parallel rightward shifts in the logarithmic concentration/response curves (competitive shifts): Competitive antagonism
3.
3 phases of drug action:: Pharmaceutical phase: Drug is released from package.
Pharmacokinetic phase: Absoprtion and distribution, metabolism and excretion
Pharmacodynamic phase: how the drug binds to the target site, stimulus and effect
4.
3 types of drug nomenclature:: Chemical name, non-proprietary, proprietary
5.
3 types of pharmacodynamic antagonists: ➢ Competitive: where two drug molecules are competing for the one receptor site
➢ Non-competitive: where an antagonist molecule binds at a site remote to the receptor site, causing a conformational change meaning that the agonist no longer fits.
➢ Irreversible: the drug forms covalent bonds to the receptor, and never leaves the receptor site
6.
4 types of anatagonism: ➢ Chemical antagonism: when drugs cancel each other out in solution
➢ Physiological antagonism: sympathetic nerves and parasympathetic nerves acting in opposition
➢ Pharmacokinetic antagonism: body reacts adversely to drugs
➢ Pharmacodynamic antagonism: where the drug binds at the receptor site/competes with the agonists
7.
Affinity: The ability of a drug to bind to the receptor site
8.
Clark's model (occupational theory model): The response is proportional to the amount of drug-receptor complexes formed. Emax (is proportional to) [Rt]
THIS IS WRONG.
Stephenson's model proved that a 100% efficacy could be achieved with a smaller amount of D-R complexes.
9.
Definition of Pharmacology: Study of the interaction of drugs with living systems.
10.
Dissociation constant: The equilibrium constant for the dissociation reaction. Is called KD
11.
EC50: The agonist concentration that produces a response which is 50% of the maximum response. It is a measure of agonist potency. pD2 = -log10[EC50]
12.
Efficacy: The ability of a drug bound to a receptor site to generate a stimulus hence producing a biological effect: a measure of receptor-effector coupling efficiency
13.
Inverse agonists: These reduce the level of activation of a receptor (agonists increase the level of activation)
14.
Molecular targets for drug action: Enzymes, carriers/transporters, ion channels, receptors
15.
Other ways in which drugs affect cells: Disruption of cells, chemical and physical properties, pH, osmotic effects.
16.
pA2: The negative log10 of the antagonist concentration at which it is necessary to double the concentration of agonists in order to produce the same response as if there were no anatagonists.
Can be used for 1) Different antagonists on the same tissue and 2) One antagonist on different tissues
Measures the potency of competitive antagonists.
17.
Partial agonists: Have affinity for the receptor, but lower efficacy than full agonists. Hence the effect never reaches 100% (maximal efficacy).
18.
Potency: Relates to the concentration of a drug which is required to produce the desired effect.
19.
Receptor is?: A cellular macromolecule which is concerned directly and specifically with chemical signals inter-and intracellularly.
20.
Receptor reserves: Leftover receptors not activated even when the drug is producing 100% efficacy.
21.
Reversible and irreversible bonds at the receptor site: Reversible: van der Waals, ionic, hydrogen
Irreversible: covalent bonds
22.
Signal transduction: The relaying of chemical or physical signals from the outside of the cell to the intracellular response mechanisms.
23.
What is a drug?: A chemical substance which is biologically active in small quantities. It is administered to produce a desirable physiological or psychological effect.
24.
What is pharmacodynamics: What the drug does to the body: how the drug binds to the target site, and how the drug acts to produce a biological effect
25.
What is pharmacokinetics: What the body does to the drug: lipid solubility, charge, and size
