Week 2 Pharmodynamics Module Flashcards
define pharmodynamics
what a drug does to the body
define pharmokinetics
what the body does to a drug
what is a drug?
an exogenous chemical compound that effects a biochemical or physiological function in a specific way
define receptor
a sensing element in a chemical communication system that coordinates the function of different cells in the body
define inert binding site
an endogenous molecule that binds to a drug but does not lead to a response (ex drugs commonly bind with albumin, and that binding does not cause any physiologic effects)
give an example of a drug that inhibits an enzyme
Statin: inhibits HMGCoA Reductase which decreases intra-hepatic cholesterol synthesis
give an example of a drug that acts on a transport protein
Digitalis: inhibits Na/K ATPase
give an example of a drug that acts on a structural protein
Colchicine: binds tubuline
what are the four families of receptors. which are membrane receptors?
ligand-gated ion channels: membrane G protein coupled receptors: membrane Enzyme-linked receptors: membrane Intracellular receptros: not in the membrane (ligand is hydrophobic)
what are three prototypes of statin?
simvastatin, lovastatin, atorvastatin
what do glucocorticoid drugs do?
anti-inflammatory agents
what are three prototypes of glucocorticoids?
dexamethasone, prednisone, hydrocortisone
Drug affinity is directly proportional to what two factors?
bond strength and structural conformation
what is an agonist?
substance that activates receptors. has affinity for receptor and intrinsic activity
what is an antagonist
substance that prevents receptor activation. affinity for receptor but no intrinsic activity
what is othrosteric binding of drugs
drug binds to active site
what is allosteric binding of drugs
drug binds at a site other than the active site
what is a full agonist?
produces 100% activation of a receptor at high concentrations
what is a partial agonist
binding results in less than 100% activation even at very high concentrations
what is an inverse agonist
binding results in a response below the basal activity
what is a competitive antagonist. can they be overcome
binds to the same site as an agonist (reduce potency). overcome by increasing agonist concentration
what is a noncompetitive antagonist. how can they be overcome?
binds to a different site than the agonist. prevent the binding of agonist or prevent the agonist from activating the receptor. reduce efficacy. cant be overcome
define potency
amount of drug needed to reach a desired effect
define efficacy
max effect a drug can produce
what are physiological antagonists
opposing pathways that exist in the body
what are chemical antagonists
receptors are not involved, activity based on chemical interactions
what is selectivity
the degree to which a drug or chemical has an affinity for a particular type of receptor
what is favorable about highly selective drugs?
they produce the intended or desired effect with minimal side effects
give an example of a selective drug
some beta blockers selectively block Beta 1 receptors in the heart but not beta 2 receptors in the lungs
a drug is selective if…
the drug interacts with only one type of receptor, and if that receptor type regulates just a few processes
a drug is non-selective if…(2 options)
if a drug interacts with one receptor but that receptor regulates multiple processes. OR if a drug interacts with multiple receptors.
which drugs are completely selective
none. increasing does of any drug will lead to side effects.
does selectivity guarantee drug safety?
no. too much of a drug can still have a negative effect
what is a graded dose-response curve? what can it tell you?
a curve that shows how different concentrations of a drug impact its effects. it can be used tom compare potency and efficacy of different drugs
what is Emax?
the maximal response or effect. biggest response a drug can produce
what is EC50
the concentration of the drug producing 50% of the maximal effect (Emax)
what to quantal dose-response curves show?
these curves tell you how drugs effect the general population. Give you ED50, TD50, LD50
what is ED50
the effective dose in which the desired effects are seen in 50% of people
what is TD50
the toxic dose for 50% of popn
what is LD50
the lethal dose for 50% of people
how do you calculate therapeutic index? TI
TI=TD50/ED50
how do you calculate the margin of safety?
MS=LD1/ED99
when is it ok to use a drug with a narrow therapeutic window (small TI)
only when no other therapeutic options exist. routine monitoring of drug levels is necessary
a wide therapeutic window has what TI?
large TI
what is this?
Quantal dose response curve
what is this?
graded dose response curve
give an example of a non-slective beta blocker?
propanolol and sotolol
what are examples of selective beta blockers
atenolol, metoprolol, esmolol
