Principles of Pharmacology 1 Flashcards
In simple terms, what is meant by pharmacodynamics?
What a drug does to the body
In simple terms, what is meant by pharmacokinetics?
What the body does to a drug
What 3 questions do we ask when analysing the pharmacodynamics of a drug?
Where is the effect produced?
What is the target for the drug?
What is the response that is produced after interaction with this target?
Where is the euphoric effect of cocaine produced?
Dopaminergic neurons in the nucleus accumbens in the brain
What is the target site of cocaine?
The dopamine reuptake protein on the pre-synaptic terminal
What is the effect of cocaine after it interacts with its target site?
It blocks the reuptake protein so dopamine remains in the synapse for longer
What are the 4 target sites for drugs? Give an example drug for each
Receptors (eg nicotine)
Transport protein (prozac)
Enzyme (asprin)
Ion channel (anaesthesia)
What is selectivity?
How closely a drug binds to its target site
How is dose related to selectivity?
Drugs can bind to multiple targets but usually have higher selectivity for one target over others. Increasing dosage can cause it to bind to other unwanted targets and produce side effects
What are the 4 types of drug- receptor interactions?
Electrostatic interactions - this is the most common mechanism and includes hydrogen bonds and Van der Waals forces.
Hydrophobic interactions - this is important for lipid soluble drugs.
Covalent bonds - these are the least common as the interactions tend to be irreversible
Stereospecific interactions - a great many drugs exist as stereoisomers and interact stereospecifically with receptors.
What is an angonist?
Something that binds to a receptor and activates/opens the function
What is an antagonist?
Something that binds to a receptor and blocks the channel/function of it
What does affinity mean?
The strength of a drug receptor interaction
What does efficacy mean?
The ability of an individual drug molecule to produce an effect once bound to a receptor
Describe levels of affinity and efficacy in full agonists
They have high affinity and efficacy
What is potency?
The concentration or dose of a drug required to produce a defined effect
How is potency measured?
ED50- estimated half maximal dose
EC50- estimated half concentration
Out of potency and efficacy which is related to dose?
Potency