Test 1 Part II Flashcards
drugs that bind via __________ bonds are more selective than drugs that bind via _________________ bonds
weak; strong
which drug-receptor bond is important to the interactions of highly lipid-soluble drugs
hydrophobic
_____________ drug-receptor bonds require a very precise fit in order for a reaction to occur
weak
most receptors are _______________
proteins
receptors determine:
- relationship between dose and effect
- selectivity of drug action
- actions of agonist and antagonists
how do receptors determine the relationship between dose and effect of a drug?
- affinity for binding determines the concentration of the drug required for a biological response
- Total # of receptors may limit the maximal effect a drug can produce
what are the different types of receptors
ligands
regulatory proteins
enzymes
transport proteins
structural proteins
spare receptors
ligand receptor type
a signal triggering molecule binding to a site on a target protein to serve a biological purpose
regulatory protein receptor types
mediate the actions of endogenous chemical signals from NT, autocoids, and hormones
what receptor types do we know the most about
regulatory proteins
enzyme receptor type
an endogenous receptor that may be inhibited or activated by binding to a drug
spare receptor type
available receptors after the max effect of a drug is achieved
_______________ is measured by the concentration of drug that is needed for drug-receptor binding
affinity
what is affinity?
the lowest concentration of drug to occupy 50% of the receptors
______________ = presence of low concentration of drug that produced drug - receptor binding
high affinity
increased affinity = ___________ potency
increased
binding affinity can be related to drug ________________, as seen in dose-response curves
potency
Drugs are defined by their _____________
potency
increased potency = ____________ EC50
decreased
what is EC50
the effective concentration required to produce 50% of that drugs maximal response
the higher the affinity of a drug to its receptor, the less ______________ required
concentration (of the drug)
increased affinity = ___________ potency = ____________EC50
increased; decreased
define potency
Very closely related to EC50. Just the concentration or dose required for 50% of the drugs max response. As EC50 drop potency goes up.
define efficacy
the ability of the drug-receptor complex to activate signal transduction –> biological response
what is efficacy dependent upon?
the ability of a drug to induce conformation change in the shape of the receptor that leads to ST and BR
drug choices are made based on ______________ rather than ______________
efficacy; potency
what is intrinsic activity
the measure of the magnitude/intensity of a biologic response produced by the EC100 relative to the maximal attainable response produced in target tissues
intrinsic activity is independent from _________________
affinity
maximal attainable response is represented by what numerical value?
1.0
the closer an alpha value of drug is to 1.0 is more of a _______________; while closer to 0.0 it is more of a _______________
agonist; antagonist
_____________________ is used to classify drugs as agonist or antagonists
intrinsic activity
intended/therapeutic response
response given to a drug that is observed in most patients
idiosyncratic response
infrequently observed and unintended response to a drug. usually caused by genetic differences in metabolism of drug
give a medication to make patient stop sneezing, and it makes them stop coughing instead. This is an example of what type of response
idiosyncratic
hyporeactive response
quantifiable response to a given dose of a drug that is diminished when compared to the response observed in most patients
hyperreactive response
quantifiable response to a given dose of a drug that is increased when compared to the response observed in most patients
hypersensitive response
allergic or immunological response to a drug
tolerance (drug response)
decreased response to a drug as a consequence of continued administration/usage
tachyphylaxis (drug response)
a rapid decline in response to administration of a drug. give once works great, then 2nd exposure does not work at all
you give a patient a steroid injection for pain in the back. the first time you do it the patient claims it worked great, so they come back to get another when it flared up again. This time; however, the patient claims there was no relief, like it didnt work. This would be an example of what type of drug response?
tachyphylaxis
paradoxical effect of a drug
opposite effect than intended
you give propranolol to decrease a patients heart rate, but it causes the patients heart rate to rise more. This is an example of what type of drug effect
paradoxical
what are all the things a provider should consider when choosing a drug to administer?
- age of pt
- sex of pt
- body size of pt
- disease state (liver/kidney compromise?)
- genetic factors
- simulatneous administration of other drugs
a patients response to a drug can be altered by
- inherited drug metabolizing enzymes
- interruptions in the active transport of the drug from the cytoplasm
- physiologic conditions that alter the endogenous receptor ligands (runner/athlete, pheochromocytoma, htn)
- alterations in the # or function of receptors
- changes in the components responsible for completing the DR complex (wrong dx, compensatory mechanism activity)
antagonist binds to receptor causing hypostimulation, then the body compensates for the depressive effect by generating more receptors, this is called ___________________
upregulation
propranolol fx as antagonist to decrease HR, if you abruptly withdraw this medication from the patient, it can result in rebound effects, like SVT, this is due to ____________________
up-regulation
_____________________ is when the body recognizes the stimulation of an agonist and tries to compensate for the increased effects by removing some of the receptors
down-regulation
the ________________ of a drug is what identifies its usefulness in medicine
selectivity
the action of a drug binding to one or a few types of receptors more tightly than others describes its __________________
selectivity
T/F: side effects are a category of selectivity
false
