Pharmacology Flashcards
Define pharmacology
The study of substances that interact with living systems, usually through binding with regulatory molecules.
Either through enhancing or inhibiting a process. In terms of drugs, there is usually a mimicking of natural processes
Define a drug
Any substance that interacts with a molecule or protein that plays a regulatory role in living systems
Name an example of an endogenous drug
Hormones (neurotransmitters)
What is a receptor?
A region of tissue or molecule that responds to a specific neurotransmitter, hormone, antigen or other substance.
Usually a protein.
What are the names of agonists in terms of their level of activity?
Full agonist Co-agonist Selective agonist Partial agonist Inverse agonist Superagonist Irreversible agonist
What is an endogenous ligand?
A ligand produced by the body and not administered by drugs
What is an agonist?
Any drug that binds to a receptor and activates it. It mimics the endogenous ligands in the body.
When a ligand leaves it usually deactivates the receptor and stops the effect.
Some ligands cause covalent changes and keep the receptor permanently activated
What are the 4 main types of receptors?
Ligand gated ion channels
G protein coupled receptors
Receptor tyrosine kinases (enzyme linked),
Nuclear receptors
What is a full agonist?
A full agonist is a chemical or drug that binds to a receptor and activates it causing an enhanced response
It mimics the endogenous ligand exactly with the same affinity and same response
What is a partial agonist?
A partial agonist is an agonist that binds to the receptor active site but is unable to cause the maximal response even if all the receptors are occupied
They usually have a lower affinity for the receptor and so don’t bind as strongly as the full agonist
Compare partial and full agonists
Partial agonists have a lower affinity for the receptor compared to full agonists
Partial agonists at lower doses produce a greater response but can never reach the maximal response
Partial agonists have a wider therapeutic window and are safer to give to patients
How do you figure out the volume of distribution?
Volume of distribution = total amount of drug / plasma concentration
What happens when a drug is bound to a protein?
It becomes pharmacologically inactive
A drug needs to be free onto
Can’t be administration, distributed, metabolised, excreted (ADME)
What is efficacy?
K
What is potency?
K
What is a non competitive antagonist?
K
What is a competitive antagonist?
K
How do G protein coupled receptors work?
Agonist causes a conformational change
What are the properties of the G Protein coupled receptors?
Receptor binding point
7 transmembrane spanning domains
How do ligand gated ion channels work?
There is a change in the cells electrical activity as a ligand binds which brings about a conformational change and then the specific ions that it is sensitive to can pass through along it’s concentration gradient
What kind of a channel is NMDA?
Ca2+
What kind of a channel is GABA?
Cl-
What kind of receptors are common in the Nervous system?
Ligand gated ion channels
How do tyrosine kinase receptors work?
Phosphorylation of the 2 tyrosine dimers on the membrane
