Pharmacodynamics 1 Flashcards
Pharmacokinetics
study of what the body does to the drug
pharmacodynamics
study of the action of drugs on the body
drug nomencleture
- chemical name
- generic name
- trade name
drugs often
mimic or block the action of our own signalling molecules
examples of natural drug sources
yew, fox glove, penicillium
receptor
generally used to describe the target molecules through which double physiological mediators produce their effects
protein targets of drugs
enzymes, transporters, ion channels, receptors
non protein targets of drugs
DNA, lipids
Principles of drug action
binding, agonism/antagonism, receptor classification, second messengers/signal amplification
4 receptor families
ligand gated ion channels
G protein coupled receptors
Kinase linked
nuclear receptors
ligand gated ion channels
ionotrophic receptors
passageway through membrane
conformational change
fast siganlling
example of ligand gated ion channel
nicotinic acetyl choline receptor
GPRC
Metabotrophic
protein with multiple subunits
example GPRC
post synaptic muscaranic acetylcholine receptor
kinase linked
inside the membrane
gene transcription and protein synthesis
response takes hours
example kinase linked
cytokine receptor - insulin receptors
“metabolic change”
Nuclear receptors
action in the nucleus - may not be specifically located in the nucleus
hours
gene transcription and protein synthesis
example of nuclear receptor
hormone - lipophilic eg oestrogeen receptor
Is a drug ever 100% specific?
no - only selective for the receptor over another
Specificity
the ability to identify the true negatives
eg 100% - correctly identify all the patients without the disease
Can therapeutic dose affect specificity?
yes - which receptors are activated
side effects at higher doses
binding is …. in 99% of situations
transient - on/off
rate of on and off
K↓1 and K↓-1
higher affinity
will bind more readily to its receptor
endogenous ligand
binds toa receptor - produced in the body
what is K↓D
the dissociation constant which is a measure of the tendency of the drug-receptor complex to dissociate
[D] [R] [DR]
K↓1 forwards and K↓-1 reverse reaction