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.
whats the difference between hangover and witdrawl
?
what theoy is this —the A process cre-ates the tranquilizing a effect of the CDP, and the B process creates the compensatory b state of anxiety.
opponent process theory
how does opponent process theory explain acute tolerance
When you take a drug, its effect will be greatest before the B processes build up. As the B processes get stronger, the strength of the A process will diminish
If you take a drug continuously for weeks or months
and maintain a fixed level of the drug in the body so that withdrawal symptoms never occur, what happens
the compensatory response builds up.
the a state almost disappears entirely (i.e., this is…) and the b state (i.e., the …effect) is more intense and longer lasting
increased tolerance
withdrawal
figure 3.3
review
is there a strong correlation between withdrawl and tlerance
no
how can asual drinkiers have high tolerance with no withdrawl
could be behavioural not physiological tolerance or rate of elimination from body is very slow
2 types of conditioning of drug effects
classical and operant
In Pavlov’s terminology, the drug was the …; the effects of the drug—the salivation and vomiting—were the …; the stimulus preceding the drug was the …; and the salivation and nausea produced by these stimuli presented in the absence of the drug was the …
unconditioned stimulus (US) unconditioned response (UR) conditioned stimulus (CS) conditioned response (CR).
The conditioning of drug effects is more complicated than it first appears because …
the UR and the CR to the drug are not always the same. Sometimes, the stimulus paired with a drug, when presented in the absence of the drug, produces a physiological response
what becomes the UR and CR in drug conditioning then
in many cases, these compensatory responses, not the initial effects of the drug, are what become conditioned to stimuli that are repeatedly paired with the administration of the drug
tolerance that is only evident only in the enviro where the drug is experienced
conditional tolerance
how is conditioned tolerance explained
the envi-ronment repeatedly associated with the drug acts like a CS. the environment associated with the administration of the drug elicits physiological responses opposite to the effect of the drug. These changes help prepare the rat for the drug and diminish its effect.
he injected a rat with saline and gave it the paw lick latency test in an environment that had previously been associated with repeated injections of morphine, the rat’s latencies would be even shorter than normal; that is, the …
animal would show hyperalgesia
This was the compensatory response that had been produced by the morphine envi-ronment through conditioning.
Alcohol has been found to be l… when it is consumed in a familiar mix (e.g., beer) compared to if the same dose of alcohol is con-sumed in a drink that does not usually contain alcohol
ess cogni-tively impairing
alcohol consumed in a usual environment (a bar) produces … than when consumed in an unusual environment
less cognitive impairment
fill in table 3.1
?
… tolerance
can protect humans and nonhumans from a heroin overdose
conditional
chronic heroin users regularly administer doses many times greater than a dose that would kill a non-tolerant user. so how does this person ever overdose on heroine
result of mixing heroin with other drugs, espe-cially alcohol. But many others appear to result from a sudden loss of tolerance.
why will people have a sudden loss of tolerance
They reasoned that tolerance to heroin is partly con-ditioned to the environment where the drug is normally admin-istered. If the drug is taken in a new setting, much of the conditional tolerance disappears, and the addict is more likely to overdose.
… may be conditioned to a particular environment where a drug is repeatedly given.
compensatory responses
physiological changes opposite to the drug’s effect. When these responses occur in the absence of the drug, they are …
withdrawal symptoms,
conditioned withdrawal symptoms disappear when the body makes its ini-tial readjustment to the absence of a drug
f does not
how do these conditioned withdrawl symptoms go away then?
extinction—that is, the presen-tation of conditioned stimuli in the absence of drug administration.
if tolerance is a result of learning strategies to compensate for the effect of a drug, then the development of tolerance should depend on the occurrence of … when a compensatory response is made.
reinforcement
participants given information or feedback about their performance, whether they were paid money or not, developed tolerance rapidly, and the other groups developed tolerance slowly, if at all: explain
participants’ knowledge that they were resisting the effects of alcohol was sufficient reinforcement for learning to resist the effects of alcohol.
If Henri Paul was that tolerant, could alcohol have played
a role in the accident?
Henri Paul was able to walk and talk normally, his intoxication prior to get-ting behind the wheel went seemingly undetected. Walking and talking are behaviors that most regular drinkers are able to practice under
the influence of alcohol; very often, those
behaviors are rewarded with social approval. Because Henri Paul was a professional driver, it would have been disastrous for him to exhibit any effects of alcohol intoxication before driv-ing. Therefore, walking and talking were likely to be the first behaviors restored by both acute and chronic tolerance. Driving is a complex task requiring many different cogni-tive and motor skills.
what is the oppoistie of tolerance
sensetization
what is sensetization
for certain effects of a drug to increase with repeated administrations
when can sensitization occur
after only a single low dose of a drug.
what are stereotyped behaviours
At high doses, stereotyped behaviors may be seen. Stereotyped behaviors are invariable, repetitive move-ments, such as head bobbing and sniffing, which are engaged in for extended periods of time and appear to have no purpose
drugs like cocaine and amphetamine, even at low doses, are able to produce symptoms of psychosis and even convulsions in chronic users, although they do not cause these effects in beginning user what is this an example of
sensitization
Like tolerance, sensitization may also be conditioned
to a particular environment
t
how is sensitization very similar to tolerance
if sensitization develops in response to repeated administration of a drug in a specific environment, then sensitization will be greatly diminished or will not appear at all when the drug is given in a different environment. Second, if sensitization results from repeated injections in a specific environment, then that environment will act as a CS for a drug-like CR.
how is sen and tol different 2
sensitization appears to be a mirror image of tolerance, except that the conditioned response is a drug-like response rather than a drug-opposite response. One way in which sensitization may differ from toler-ance is in its persistence. Even a single dose of a drug can create long-lasting sensitization.
When the drug-like CR (activation) is elicited in conjunc-tion with the drug effect (also activation), what is the result
there is an enhanced drug effect
how long can sensitization last
increases with time and never dissipates
what is cross sensitization
(stress can do) animals with a sensitization to mor-phine will also show increased behavioral activation to cocaine and amphetamine, and vice versa.
Stress-induced cross sensitization of drug effects appears to result from the impact of the hormone … on the development and functioning of the meso-limbic and mesocortical dopamine pathways
corticotropin-releasing factor (CRF)
what neuronal effect is responsible for sensitization
Sensitization clearly involves the brain’s general motiva-tion control system, which is responsible for arousal and approach to both conditioned and natural incentives such as food and receptive sexual partners
Sensitization of this system has been proposed as an explanation for the excessive “wanting” (craving) in addiction elicited by exposure to a drug or its conditioned cues
A part of this system that becomes sensitized and hyperactive is the mesolimbic dopamine pathway.
An addi-tional component of the brain’s motivational circuitry is the …. Hyperactivity in this pathway may be responsible for the sensitization of stereo-typic behaviors that eme
nigrostriatal dopamine pathway
The expectation of being influenced by a drug is largely what drives the …
The expectation of being influenced by a drug is largely what drives the placebo effect
…—a top-down pain-relieving pathway from the cortex to a pain control center in the lower brain that is capable of blocking pain.
expectation mechanism
These brain regions are involved in cogni-tive control, anxious anticipation, and the motivational and affective responses to … Decreases in activity in these same regions appear during placebo anal-gesia
expectation of pain.
Conditioned placebo effects, resulting from learned asso-ciations between particular stimuli and pain relief, involve changes in activity in the …—a region of the brain that processes reward
striatum
the placebo effect can be blocked by naloxone what does this tell us
he placebo effect involves the same pain control mecha-nisms as those of morphine and other opioids. (but still some effect so is working on more than one system)
… (the belief that a drug or medical procedure will be effective) seems to be the most important factor in eliciting a placebo effect
Positive expectation
Expectation can be created by p….
ast expe-rience with other medications and treatments, or enhanced by cues that signal that they have been given an active sub-stance.
In addition to expectation, the patient’s…2 can also be important in generat-ing the placebo effect
desire for an effective treatment and motivation to allevi-ate distressing symptoms
deception is not required for placebos to exert their beneficial effects.
t Compared to patients in the con-trol group who did not take pills, those who knowingly took placebos reported significant improvement in their IBS symptoms
T: that a placebo can generate adverse side effects in participants.
nocebo effects
does self admin influence placebo
yes more likely to develop adicition becuase increased dopamine effect when self admin
how do novel enviros influence
when these drugs are administered in a novel setting, they exert differ-ent effects on the nervous system, effects that are likely to make them more addictive
low-dose drug administration tends to increase … and, with repeated administrations, this effect shows sensitiza-tion.
motor behavior
All behavior is under the control of the …
All behavior is under the control of the nervous system
2 main types od cells in nervous system
glial cells and neurons
Neurons are ….
excitable cells that analyze and transmit information
neurons are responsible for …
behaviour
what do glial cells do
a supporting structural role, gluing neurons in place
how do glial cells have a metabolic role
supplying neurons with oxygen and nutrients and removing waste.
