Chapter 3 Flashcards
what is tolerance
Drug tolerance is defined either as the decreased effec-tiveness (or potency) of a drug that results with repeated administrations, or as the necessity of increasing the dose of a drug in order to maintain its effectiveness after repeated administrations.
all the effects of a drug diminish at the same rate
f dif tolerances for each effect
it is more appropriate to think of tolerance developing to the ….
…. rather than to the drug itself
various effects of a drug
what is cross tolerance
when tolerance to one drug diminishes the effects of another drug
when do we usually see cross tolerance
memvbers of the same drug class
why is cross tolerance with members of same drug class
evidence that the drugs may be producing their effect by common mechanisms.
does tolerance last indefinatly
no may also depend of environment
does tolerance always develop after repreated administrations
it can also occur during a single drug administration.
T: —tolerance that has developed during a single administration.
acute tolerance
what is acute tolerance
The effect will peak before the blood level peaks, and the effect will be gone before the drug is entirely eliminated from the body.
figure 3.1
explain whats happening in graph
what does pharmacokinetic mean
drug movement”
3 areas of pharmacokinetics?
absorption, elimation distribution
an increase in the rate or ability of the body to metab-olize a drug, resulting in fewer drug molecules reaching their sites of action.:T
Pharmacokinetic tolerance (also called metabolic tolerance or dispositional tolerance
what is Pharmacokinetic tolerance (also called metabolic tolerance or dispositional tolerance usually the result of
an increase in the level of an enzyme the body uses to break down the drug
how does pharm tolerance change effect drug has
all effects of the drug will be dimin-ished because of the diminished concentration of the drug at the site of action is less
can pharm tol create cross tolerance
yes
The term pharmacodynamic means “…”
drug change” and refers to a drug’s effects on the body, including various physiolog-ical processes
Pharmacodynamic tolerance (also called physio-logical tolerance or cellular tolerance) arises from …
adjustments made by the body to compensate for an effect caused by the continued presence of a drug.
pharmdynamic tol is the result of …
homeostasis to a set point
how does pharodynamic effect drug effect
This means the drug will have a smaller and smaller effect the more it is adminis-tered. because body gets better at returning to set point
nerve cells communicate with one another by releasing a substance called a …, which interacts with specialized molecules called … sites on the membrane of a neighboring nerve cell.
neurotrans-mitter, receptor
Some drugs work by blocking these receptor sites and reducing the effect of the neurotransmitter. what is bodies reponse (pharmodynamic)
There is a homeostatic mechanism that detects when this happens and the cell can respond in a number of ways, such as by manufacturing more receptor sites, increasing receptor-site sensitivity to the neurotransmitter, or by increasing the synthesis and release of the neurotransmitter.
There is a homeostatic mechanism that detects when this happens and the cell can respond in a number of ways, such as by manufacturing more receptor sites, increasing receptor-site sensitivity to the neurotransmitter, or by increasing the synthesis and release of the neurotransmitter. :T
upregulation
If the drug stimulates the receptor sites rather than blocking them, an opposite compensatory effect called …can occur.
If the drug stimulates the receptor sites rather than blocking them, an opposite compensatory effect called downregulation can occur.
what is needed for pharndynamic to develop
opportunity to interfere with the functioning of the organism - some sort of feedback
tolerance will develop (or will develop much more quickly) only in a circumstance where …
a drug places a demand on an organism’s homeostatic mecha-nisms.
tolerance to the analgesic (pain-relieving) effect of mor-phine develops… in rats that are subjected to painful stimuli after being given the drug
faster
what is behavioural tolerance
Tolerance can be influenced by learning—through experi-ence with a drug, an organism can learn to decrease the effect that the drug is having
what cause withdrawl symptoms
are physiological changes that occur when the use of a drug is stopped or the dosage is decreased.
drugs of the same family generally pro-duce similar withdrawal.
t
how can you stop withdrawl symptoms what is this called
giving the drug or one similar to patient This phenome-non is known as cross dependence.
The extent of withdrawal may also depend on the …2
The extent of withdrawal may also depend on the drug dose and administration schedule.
Withdrawal symptoms usually begin some hours after
the use of a drug has ceased, but they can be produced much more quickly by giving an …
antagonist drug.
what is naloxone
a powerful antagonist to morphine, rapidly blocks all morphine effects soon after it is given by block-ing the receptor used by morphine. When naloxone is given to morphine-dependent humans or laboratory ani-mals, severe withdrawal can be seen within minutes.
2 ways we define dependance?
(a) to describe a state in which discon-tinuation of a drug causes withdrawal symptoms, and (b) to describe a state in which a person compulsively takes a drug—this state is often described as addiction
are addiction and dependance the same thing?
We now know that this is not the case. People who experience with-drawal symptoms when a drug is discontinued do not neces-sarily take that drug compulsively, and people may take a drug compulsively even though they will not experience withdrawal symptoms when they stop.
what cause withdrawl symptoms
when the drug is discontinued and its effects disappear, it takes some time for the body to readjust to the drug’s absence. During this readjustment, the com-pensatory responses are what cause withdrawal symptoms.
They proposed that abused drugs stimulate an A pro-cess that creates a what 2 states
euphoric (pleasant) a state, but that soon after, a compensatory B process is evoked that creates a dysphoric (unpleasant) b state
what is the a b state theory called
oponent process theory (withdrawl can occur after each administration
what the difference between withdrawl and hangover. give alc example
refers to the aftermath of the acute effects of a drug, such as when you go out drinking at night and then feel sick the next day. Many of the symptoms of an alcohol hangover are the direct result of toxic effects of alcohol, such as dehydration or stomach irritation which remain after the intoxication. But some effects, like sensi-tivity to lights and noise, can be thought of as brief with-drawal symptoms that are compensatory responses to the effects of alcohol.