Pharmocology Flashcards
What is pharmacology?
The study of drug action on animals, organs, tissues and cells
What is the difference between a drug and a toxin?
Nothing except the dose
What does endogenous mean?
Within the body
How do drugs work?
Mimic/blocking endogenous molecules
What is a pharmacon/ligand?
A biologically active substance (drug)
Can be hormone (water soluble), cytokines (small peptides), growth factors, neurotransmitters, pheromones
Exogenous derived pharmacons are usually what type of molecules?
Organic and cyclic
Drugs can have specific effects related to their chemical structure. How do these drugs work?
Bind to specific targets
What are examples of drugs that have non-specific effects (related to their physiochemical characteristics)?
Antacids
Laxatives
Purgatives
Diuretics
What are the 4 main targets for pharmacons?
RECEPTORS
Enzymes
Ion channels
MRNA/DNA
What is affinity?
Overall strength of binding
What is specifity?
The geometry, how specific
What is the Structure Activity Relationship?
Study of the structure of a molecule and how well that relates to its activity
(Want to optimise both)
When trying to create a drug for a disease, what is the order of events?
Identify disease
Identify target
Synthesise selective and small ligands
Assess function
What is the LD50?
Lowest dose that kills 50% of animals
What is the therapeutic index?
The ratio of the lowest effective dose: lowest fatal dose
Anaesthetics are very dangerous, does this mean they have a low or high therapeutic index?
Low
What is pharmokinetics?
The mechanism of drug action
What is the mechanism of drug action? MADE
Metabolism
Absorption
Distribution
Elimination
What are most receptors?
Cell surface proteins
What is an agonist drug?
A drug which binds to and has an effect on a receptor (conformational change)
What is an antagonist drug?
Drug which prevents an effect (conformational change) on a receptor
What is an example of an agonist drug?
Histamine
Causes the release of gastric acid
What is an example of an antagonist drug?
Ranitidine
Blocks histamine receptors
Prevents gastric acid secretion
What is an opioid?
Drug with morphine like effects
What is the difference between an opiate and an opioid?
Opiates are natural
Opioid is natural and synthetic
What is the Law of Mass Action?
The more drug there is, the more binding there is (up until saturation)
What is affinity?
How well a molecule binds
What is efficacy?
How well a molecule does seething
What levels of affinity and efficacy do agonists have? What about antagonists?
High affinity, high efficacy
High affinity, low efficacy
Why are log scales used to compare drugs?
Easier to interpret
How do agonist drugs work? (3 steps)
Reception (& conformational change)
Transduction
Response
What is the cascade effect?
A receptor activates something which activates another - ends up with large amount affected
What is a metabotropic receptor?
Membrane receptor which acts via the second messenger model
What is an example of a metabotropic receptor?
G protein coupled receptor
What are G protein coupled receptors?
Single polypeptide, work by second messenger model and inhibiting ion channels
G protein coupled receptors are mainly to do with which sense?
Olfaction
What are G protein activated enzymes? Give examples
Enzymes acted upon by G proteins
E.g. cAMP, cGMP
What are the 2 mechanisms to switch a protein on?
Phosphorylation
GTP binding to G proteins
What are G proteins?
Proteins acting as an on/off switch
Switched on by the binding of GTP
Switched off by the binding of GDP
What causes the airways to constrict in asthma? How is this treated?
Bronchospasms
Noradrenaline
Adrenoreceptors can be B1, B2. What does B1 receptor do?
Increase heart rate and contractility
What do B2 adrenoreceptors do?
Cause vasodilation
