Week 2 Flashcards
What is pharmacodynamics?
What the drug does to the body.
What has affinity and efficacy for a receptor?
An agonist- it binds to and activates a receptor
Describe a full agonist:
Produces a full response while occupying a relatively low proportion of receptors.
Describe a partial agonist:
Produces less than a full response while fully occupying their receptors
This type of agonist produces an opposite response to that of a typical agonist, yet it binds to the same receptor bonding sites.
Inverse agonist
This has affinity but to efficacy for a receptor.
Antagonist “blocker”
Describe a competitive antagonist:
Binds to the same receptor site as the agonist but does not activate it.
This type of antagonist binds to the agonist not the receptor.
Chemical antagonist
Describe an allosteric/noncompetitive antagonist:
Binds to an allosteric site producing a conformational change in the receptor site so that the agonist cannot active the receptor site.
The likelihood a drug will bind to a receptor.
Affinity
A dose of drug just sufficient to produce a pre-selected effect.
Threshold
An exaggerated response of two drugs working together to produce more effect than the drugs separately.
Synergism
The phenomenon in which a drug reaches a max effect, so that increasing the drug dosage does not increase the effectiveness.
Ceiling effect
A lower LD50 is indicative of:
Increased toxicity
The ratio between when a drug is safe and effective bs when it is toxic:
Therapeutic index
When the T.I. is large the dose is:
Safe I.e. penicillin
When the T.I. is small the dose is:
Needs to be carefully monitored ( warfarin)
Increasing the dose of a drug with a small/ narrow TI:
Increases the probability of toxicity
When receptors become more sensitive and more receptors are made:
Upregulations
Ex: exercise, pregnancy
Receptors become less sensitive to drug/ hormone, receptors break down over time, lose ability to response to drug/hormone:
Downregulation
Ex: long term opioid abuse , type 2 diabetes
When 2 drugs are given that act on the same receptor but do not produce an exaggerated effect.
Additive effect
Ex: 2 drugs given to control HTN
Most common type of receptor:
g-protein coupled receptors
Second messengers are required for:
Hydrophilic ligand
What can effect pharmacodynamics:
Individual characteristics such as age, sex, ethnicity