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
How do nuclear receptors work?
K
Which type of receptors are the slowest?
Nuclear receptors
What is the order of action of the four main classes of receptors? State the general time period
Ligand gated ion channels (milliseconds)
GPCR (seconds)
Receptor tyrosine kinase (minutes to hours)
Nuclear receptor (hours)
What factors do you have to consider in drug design?
K
What is tachyphylaxis?
Acute tolerance
What is tolerance?
K
What is buccal delivery?
Spray
Mucoadhesive
What is intravenous delivery and what is it’s bioavailability?
Injection
100%
Name different type of drug administration
Oral Intravenous Intramuscular Subcutaneously Rectum Inhalation Transdermal Topical Sublingual
Why is the oral bioavailability low?
Some of it goes to the fat, plasma, muscle
How long do orally administrated take to work?
5-30 minutes
What does sublingual administration mean and how does it work, how long does it take?
Taking a drug under the tongue
Bypasses the 1st pass metabolism (the liver) and enters the systemic blood directly
2-3 minutes
What does transdermal administration mean and give an example?
Applied to skin
Crosses the skin to enter systemic blood supply
Nicotine patches
Define clinical pharmacology
K
Define a medicine
K
Define therapeutics
K
Explain 1st order metabolism
K
Explain zero order metabolism
I
