Pharmacodynamics Flashcards
What is pharmacodynamics?
This is what a drug does to the body
What are the 4 main types of receptors?
- Ligan-gated
- G-protien
- Kinase
- DNA coupled
What is a ligand gated receptor?
It is when ligand must bind to an open channel (transmembrane protiens) *quick acting
What is a g-protein receptor?
crosses 7 times membrane transmembrane receptor
*quick acting
What is a kinase receptor?
when receptors must pair up
*takes hours
What is DNA coupled receptor?
binds ligand to intracellular receptor and DNA to suppress gene expression
*takes hours
What else can drugs bind to other than receptors?
Enzymes and non-human cells
What does it mean if a drug is specific?
It binds to only one type of receptor (only alpha, or only beta, but not alpha and beta)
What does it mean if a drug is sensitive?
It bind a few subtypes of the receptors (binds Beta, but only B1, and not B2)
What is an agonist?
Causes something to happen; fits perfectly in a receptor
What is an antagonist?
Stops or slows something from happening; it is not a perfect fit.
What is a competitive antagonist?
It is when the highest concentration between two drugs wins.
If there are more antagonist molecules, then it will block the agonist and the agonist’s effects.
What is a non-competitive antagonist?
binding is more permanent - antagonist takeover
What is a partial agonist?
diminished response
What is an Emax for the dose response curve?
maximal response of a drug when all the receptors are saturated.
What is ED50 for the dose response curve?
how much drug/meds needed to get 50 percent of desired response.
If the ED50 is low, then this means that the drug is more potent
What are some other forms of antagonist?
- Chemical - when you mix the effects are diminished.
- Physiologic - two drugs have opposite effects
- Pharmacokinetic - metabolism changed (CYP)
- Receptor changes - long term exposure to agonist leads to desensitization
What is the therapeutic index?
It is the ratio between ED50 and TD50.
You want a high narrow therapeutic index so there is a lot of room between the dose that people need and the dose that would be toxic to them.
What does the Naranjo scale do?
It helps to decide if someone is experiencing an AE
What are the causes of ADRs?
Age, genetics, other DDIs, HCP errors, patients not adhering to meds
