Block A Lecture 1: Introduction to Pharmacology Flashcards
What is pharmacology?
The study of the mechanisms of action, uses and unwanted effects of drugs on living tissues
(Lecture 1, Part 1, Slide 5)
What is a drug?
A substance that modifies the activity of living tissue either positively or negatively
(Lecture 1, Part 1, Slide 5)
What is physiology?
The science of how living tissues function
(Lecture 1, Part 1, Slide 5)
What 2 effects can drugs have on physiology?
It can interfere with either normal or abnormal physiology
(Lecture 1, Part 1, Slide 5)
What is therapeutics?
The study or use of pharmacological agents in disease states
(Lecture 1, Part 1, Slide 6)
What can many therapies produce?
Unwanted adverse effects
(Lecture 1, Part 1, Slide 6)
What is pathology?
The study of the causes and effects of a disease or injury or of disease in general
(Lecture 1, Part 1, Slide 7)
What is an agonist?
A drug or naturally occurring body substance that directly causes a measurable response, which can either be excitatory or inhibitory, depending on what receptor is being activated
(Lecture 1, Part 1, Slide 10)
What is affinity?
How strongly a substrate / drug binds to its enzyme / receptor
(Lecture 1, Part 1, Slide 10)
What does efficacy mean?
The ability of a drug to activate the receptor (elicit a response)
(Lecture 1, Part 1, Slide 10)
Do agonists have affinity, efficacy or both?
They have both affinity and efficacy
(Lecture 1, Part 1, Slide 10)
What is a concentration-response curve?
A graph used to measure how effective an agonist is - with agonist concentration being on the X axis and the response elicited (as %age max of the tissue) on the Y axis
(Lecture 1, Part 1, Slide 11)
What is an EC50 value?
The concentration of the drug (agonist) when it is acting at 50% of its maximum effective response
(Lecture 1, Part 1, Slide 11)
What shape of curve should a good drug create on the concentration-response curve?
A sigmoidal (“S”) shaped curve
(Lecture 1, Part 1, Slide 11)
What does a concentration-response curve graph allow?
Comparison of EC50 values
(Lecture 1, Part 1, Slide 12)
Does a lower EC50 value equal a more or less potent drug?
More potent
(Lecture 1, Part 1, Slide 12)
What are the 3 types of antagonism?
Pharmacological, Chemical and Physiological
(Lecture 1, Part 1, Slide 13)
What is pharmacological antagonism?
When drugs counteract each other by acting on the same receptor type
(Lecture 1, Part 1, Slide 13)
What is chemical antagonism?
When one drug antagonises the action of another by chemically combining with it
(Lecture 1, Part 1, Slide 13)
What is physiological antagonism?
When two drugs counteract each other by producing opposing effects on different receptors
(Lecture 1, Part 1, Slide 13)
Do antagonists have affinity, efficacy or both?
They have affinity but no efficacy - meaning no directly measurable effect
(Lecture 1, Part 1, Slide 13)
Name the 3 ways that an antagonist can act in.
Competitive
Irreversible-competitive
Non-competitive
(Lecture 1, Part 1, Slides 15,16 and 17)
What is competitive antagonism?
Drugs competing to bind the same receptor
(Lecture 1, Part 1, Slide 15)
What does occupancy refer to?
The proportion of the receptors to which the agonist is bound to
(Lecture 1, Part 1, Slide 15)
How can competitive antagonism be reversed?
By increasing the concentration of the agonist, enabling it to out-compete the antagonist and restore tissue responses
(Lecture 1, Part 1, Slide 15)
What is reversible competitive antagonism described as?
Surmountable - as it can be reversed
(Lecture 1, Part 1, Slide 15)
What are the 2 key features in the concentration response graph of competitive antagonism?
A shift of the agonist concentration response curve to the right (without changing the slope or max response)
A linear relationship between agonist and antagonist concentration (as long as it is reversible)
(Lecture 1, Part 1, Slide 15)
What is irreversible competitive antagonism?
When the bond between the antagonist and the receptor is so strong that even increasing concentrations of agonists cannot displace the antagonist
(Lecture 1, Part 1, Slide 17)
What is usually the reason that a competitive antagonism is irreversible?
Covalent bonding between the antagonist and the receptor
(Lecture 1, Part 1, Slide 17)
What is non-competitive antagonism?
Antagonists which act at sites other than the agonist binding site
(Lecture 1, Part 1, Slide 17)
How can an agonist and an antagonist have the same effect?
By acting on different receptors and receptor locations
e.g hyoscine antagonist reducing muscle contraction and morphine being an agonist for opioid receptors - causing a reduction in acetylcholine and therefore contractions
(Lecture 1, Part 1, Slide 18)
What is a full agonist?
An agonist which can produce a maximal response from a tissue
(Lecture 1, Part 1, Slide 19)
What does it mean for an agonist to produce a maximal response?
It makes the tissue produce the largest response it possibly can
(Lecture 1, Part 1, Slide 19)
What is a partial agonist?
An agonist which can only produce a sub-maximal response
(Lecture 1, Part 1, Slide 19)
Why was synthetic chemistry a huge turning point in pharmacology?
As it enabled new synthetic drugs to be created
(Lecture 1, Part 2, Slide 3)
What did Paracelsus say?
“All things are poisons for there is nothing without poisonous qualities. It is only the dose which makes a thing a poison”
(Lecture 1, Part 2, Slide 5)
What is the the margin between the therapeutic (desired) and toxic (undesired) effects called?
The therapeutic range
(Lecture 1, Part 2, Slide 6)
What are the symptoms of botulinum toxin?
Muscle paralysis and respiratory failure
(Lecture 1, Part 2, Slide 7)
What 5 things can botulinum toxin (Botox) be used to treat?
Removal of facial wrinkles
Severe underarm sweating
Cervical dystonia ( a neurological disorder causing severe neck and shoulder muscle contractions)
Blepharospasm - uncontrollable blinking
Strabismus - misaligned eyes
(Lecture 1, Part 2, Slide 8)
What is iatrogenicity?
The capacity of a drug to produce a disease from the side effects or inappropriate prescribing of the drug
(Lecture 1, Part 2, Slide 9)
What is tetratogenicity?
The capacity of a drug to produce abnormalities of the unborn child or foetus
(Lecture 1, Part 2, Slide 9)
What is thalidomide?
A drug used to treat morning sickness in pregnant women, the R (right hand) form is the therapeutic form whereas the S (Left hand) form is teratogenic
(Lecture 1, Part 2, Slide 10)
What 3 ways are drugs studied?
In vivo
Ex vivo
High throughput screening
(Lecture 1, Part 2, Slide 11)
What are 4 examples of drug targets?
Ion channels (open or closed)
Enzymes
Transporters / carriers
Receptors
(Lecture 1, Part 2, Slide 12)
What do receptors do?
They receive and transduce signals that may be integrated into biological systems
(Lecture 1, Part 2, Slide 13)
Why are receptors needed in physiology?
Co-ordinates the activities of the bodies cells and organs
(Lecture 1, Part 2, Slide 14)
