Quiz 1 Flashcards
clinical pharmocology
the study of drugs and their interactions with living systems
therapeutic objective
the objective of drug therapy is to provide maximum benefit with minimum harm
since drugs are not ideal, skill and care must be exercised if treatment is to result in more good than harm
nurses have a CRITICAL responsibility in achieving the therapeutic objective
MEC
minimum effective concentration
the plasma drug level at which a decrease will cause the drug to show no therapeutic effects
a drug must be present at a level at or above the MEC but below the toxic concentration
- toxic concentration- plasma drug level at which toxic effects begin
plateau/ steady state
the evenly distributed concentration of a drug, occurs when the amount of drug eliminated equals the dose administered
this state is approx. achieved in four to five half-lives
half life
the time needed for the plasma concentration of a drug to be reduced by 50%
very imp. b/c it determines frequency of dosing, dosing interval
drugs w/ a shorter half life need short dosing intervals
drugs w/ a longer half life need long dosing intervals, careful to not lose the therapeutic effect
drug selectivity
elicits ONLY the response for which it is given
unfortunately, there is not such thing as a selective drug
BUN
blood, urea, nitrogen test
checks for kidney function
GFR
glomerular filtration rate
checks for kidney function and how well they can excrete waste
creatinine clearance
a kidney function test
creatin is a chemical waste product which is used to supply energy to the muscle
creatinine is the end product of that energy being used which is then excreted in the kidneys
creatinine varies due to muscle size
drug schedules
schedule I- high abuse potential, no accepted medical use
schedule II- high abuse potential, accepted medical use
schedule III- less abuse potential than II, moderate dependence liability
schedule IV- less abuse potential than II drugs, limited dependence liability
schedule V- less abuse potential and very limited dependence
affinity
strength of attraction b/w a drug and its receptor
high affinity drugs have a strong attraction for receptor sites
- drugs w/ a high affinity are very potent
drugs w/ a low affinity have to be present in the body in high concentration to elicit a response
intrinsic activity
the ability of a drug to activate a receptor upon binding
drugs w/ a high intrinsic activity have maximal efficacy
- maximal efficacy- the largest effect that a drug can produce
these drugs have the ability to produce an intense response
agonists
activate receptors have a high affinity have a high intrinsic activity they mimic the action of endogenous regulators - i.e. hormones, neurotransmitters they do not give cells new actions
antagonists
prevents receptor activation by endogenous molecules and drugs
has a high affinity
has no effect on its own so that our own receptors don’t react to it
binds to receptors and blocks them from other drugs or molecules :. prevents activation of receptors by antagonists
competitive antagonists
binds reversibly to receptors
competes w/ agonist for receptor sites
produces receptor blockades
receptor site will be occupied by whichever agent [agonist or antagonist] has a higher concentration or a higher affinity
non-competitive antagonists
bind reversibly to receptors
- rarely used therapeutically
reduces the maximal response that an agonist can produce
only way their effect is stopped is when the cell it is bound to dies or it is replaced
partial agonist
an agonist w/ moderate intrinsic activity
maximal effect is lower than a full agonist
not used therapeutically b/c it can act as an agonist or an antagonist
pregnancy categories of medications
category A- least dangerous
category B, C, D- progressively more dangerous than category A
category X- most dangeous
steps of nursing process in drug therapy
assessment [pre-administration]
- ID core drug ad pt. variables
– variables- health status, life span, gender, ethnicity, lifestyle, etc.
- hx taking, health status, drug hx, physical exam
analysis/ nursing dx
- compare and contrast drug and pt. variables
- judge the appropriateness of therapy, ID potential health problems, formulate nursing dx
planning
- maximize therapeutic effects and minimize adverse effects
- individualized
intervention
evaluation
administration of two or more drugs
intensification of effects
- potentiative- when taking 2 med.’s, one drug may intensify effects of the other drug
– the effect of only ONE of the two drugs is increased
- it either will increase the therapeutic effect or increase the adverse effect
reduction of effects
- inhibitory- interactions result in reduced drug effect
– it either will reduce therapeutic effect or reduce adverse effects
idiosyncratic response
it is an unusual, abnormal or peculiar response to a drug
sometimes this response is referred to as a paradoxical response
these responses are thought to occur b/c genetic enzymes deficiencies can alter the drug’s metabolism
additive effects
this occurs when two or more “like” [like in terms of effects] drugs are combined, and the result is the sum of the individual drug’s effects
synergistic effect
this occurs when two or more “unlike” [unlike in terms of effects] drugs are used together to produce a combined effect and the outcome is a drug effect greater than any either drug’s activity alone
antagonistic interaction
it is an interaction that is the opposite of synergism
it results in a therapeutic effect that is less than the effect of either drug alone b/c the second drug either diminishes or cancels the effect of the first drug
