Pharmacodynamics Flashcards
(20 cards)
What is pharmacodynamics?
Study of how drugs act on the body
What is a drug?
A chemical entity that alters body function which we use for prevention or treatment of disease
What are the 2 main types of drugs
Small molecules
Biologics
Describe small molecules and give an example drug
They are simple molecules that are Chemically synthesised. They are easy and cheap to synthesise. e.g. aspirin
Describe biologics and give an example drug
Biologically synthesised which makes them expensive to create. They have high target specificity and are derived from human proteins.
e.g. etanercept which narrowly targets TNF
What is a drug target ?
A macromolecular component of a cell which a drug interacts with to produce a response.
what are the four types of drug targets?
Enzyme linked receptor
Ion channel linked
G protein linked
Nuclear (gene) linked
what is affinity?
Measure of propensity (inclination) of a drug to bind to its receptor
What is efficacy?
Ability of a bound drug to change the receptor in a way that produces an effect
What does a drug response curve show?
The relationship between drug concentration and the drug’s effect (response)
Define an agonist
A drug that binds to and activates a receptor to augment the natural activity
define an antagonist?
A drug that binds to a receptor and blocks a receptor’s natural activity
What are the two types of agonists?
Full - an agonist with maximal efficacy
Partial: an agonist with less than maximal efficacy
Describe the two types of adverse effect of drugs?
Type A: related to the intended pharmacological action of the drug
TYpe b: effects are unrelated to the known pharmacological action
What are the differences in occurrence, causes and deadliness of the two types of adverse effects?
Type A: common. predictable, usually dosage related, is not life threatening
Type B: uncommon, unpredictable, when they occur they are life threatening, not dosage related.
What is ED50?
mean effective dose 50: dose at which 50% of the population manifests a given effect
what is TD50?
Mean toxic dose 50: dose at which 50% of the population manifests a given toxic effect
What is LD50
Mean lethal dose 50: dose which kills 50% of the population
what is the calculation for therapeutic index?
TI = LD50 or TD50 / ED50
Is a high or low TI better for a drug?
A high TI
