6.14 Pharmacodynamics and Drug Receptor Mechanisms Flashcards
What is Efficacy?
Greatest effect an agonist can produce if dose is take to highest tolerated level
What is potency?
refers to the EC50 or ED50 of a drug required to produce 50% of the drugs maximal effect.
What is an example of a full agonist?
Epinephrine 100 percent effect!!!
What is an example of a partial agonist?
Formoterol 63 percent effect
What is an example of an inverse agonist?
Propranolol -37% effect
What is EC50?
Effective concentration
What is ED50?
Effective Dose
What is a partial agonist?
Are drugs that bind to and activate a given receptor but have only partial efficacy at the receptor relative to a full agonist
What is a full agonist?
Bind and have affinity for a receptor producing full efficacy at that receptor.
Can a partial agonist act as an antagonist?
Yes a partial agonist can act as antagonist with increasing dose decreasing the effects of a full agonist (must be fixed concentration). Thus leading to a overall decreased response. Good to use if you want to decrease the overall effect but not turn it off.
What is a competitive antagonist?
- Binds to active site and prevents agonist from binding.
- Reversible
What is a non competitive antagonist?
Bind to an active site or allosteric site( effectively irreversible) , binds active site with covalent bond or high affinity, irreversible.
What is pharmacogenomics?
Is the study of genetic variations that influence individual response to drugs
What is Pharmocodynamic variability?
- Side effects
- Drugs are selective rather than specific actions.
What is the Therapeutic Index?
- Represents the estimate of the safety of the drug.
- Higher the therapeutic index the safer the drug is.
- Ti= Td50/Ed50
- Td50=toxic dose
- Ed50=Effective dose
