Chapter 7 Flashcards
what are tranquillizers
anxiolytics. they are used to treat anxiety disorders and agitation
what are sedative-hypnotics
drugs that are used to sedate and aid sleep
what type of tranquilizer or sedative hypnotic accounts for roughly two thirds of all psychotropic drug prescriptions?
benzodiazepines
what is the principal mechanism of action of anxiolytics and sedative hypnotic drugs
they are modulators of GABA(a) activity
What is the primary pharmocokinetic difference between sedative hypnotics and tranquilizers
sedative hypnotics have a fast kinetic profile. they are fast acting, and have only a short effect.
tranquillizers are slower acting and thus have a longer effect
what is the primary situation that barbiturates are still used today
for severe seizures (like phenobarbital) or severe headaches (butalbital)
Are barbiturates acids or bases
acids
are benzodiazepines acids or bases
acids
are Z-drugs acids or bases
acids
What is the pKa of barbiturates
8, with a therapeutic index of 3-4
what is the pKa of benzodiazepines
3.5-5, with a very high therapeutic index
what is the pKa of Z-drugs
5.6 or so
absorption from the ____ is more rapid than through a(n) ______
- digestive system
- intramuscular site
why is absorption faster through the digestive system than intramuscularly
the drugs bind to protein, which occurs more readily at an intramuscular injection site than it does in the digestive tract
how long does it take for Z-drugs to reach peak concentration
as little as about an hour
“the redistribution of benzodiazepines following absorption into the bloodstream creates a:”
two phase excretion curve
what is a two phase excretion curve
the first phase of excretion occurs when there is a rapid drop in levels as it is distributed throughout the bloodstream. in the second phase, levels begin to drop slower as when the original drug is broken down, it is replaced by other molecules that are slowly released from body fat (active metabolites !!!!!!)
nordiazapam is an active metabolite released from which drug
diazepam. its right there in the name brother
Barbiturates, Benzos, and Z-drugs are all positive _____ (nt) modulators
GABA(a)
what do barbiturates, benzos, and Z-drugs do for GABA
they increase the ability for GABA to open the Cl- ion channel
what can barbiturates do at high doses in terms of inhibitory effects
at high doses it is able to open ion channels themselves, without GABA present
why can Z-drugs work as sedatives, without having any anti-anxiety effects
because Z-drugs only target GABA alpha 1, 2, and 3, but not 5
which type of GABA receptor is responsible for sedation, as well as the amnesic and anticonvulsant effects
GABA alpha 1
which type of GABA receptor is involved in muscle relaxation, but also largely in learning and memory
GABA alpha 5
benzodiazepines are known to also enhance the effects of ____, another inhibitory transmitter
adenosine
what happened following one administration of diazepam in mice
neuroplastic changes regarding glutamate activity in the brain
benzodiazepines that do not modulate activity of ________ containing GABA receptors are less reinforcing than those that do
alpha 1
what is different about flunitrazepam (Rohypnol) between humans and non-human
generally, human preference is reflected in non-human studies. for flunitrazepam however this is not the case. while humans show preference for it, non-humans do not
what is the effect of benzodiazepines on REM sleep
they decrease the percentage, however this effect does develop some tolerance after a few weeks of use
what happens when someone discontinues use of a benzodiazepine being used for sleep
as part of withdrawal, they may experience REM rebound where there is an increase in REM and therefore also rebound insomnia
what is different about discontinuing flunitrazepam when it comes to sleep
unlike other benzodiazepines, ceasing use does not seem to cause rebound insomnia
what are the two main effects of benzodiazepines on memory
- no effect on retrograde memory, however they do have anterograde effect
- even at low doses they cause deficits in explicit memory, but have no impact on implicit memory
what effect do Z-drugs have on memory
the most common Z drugs can cause explicit verbal memory impairment
which type of sedative hypnotic is associated with complex behaviours like sleepwalking, sleep driving, and hallucinations
Z-drugs
when taken recreationally, benzodiazepines are often combined with another drug. the two most common are:
alcohol and methodone*
*methodone users often take it in order to boost the effects of the methodone
what is the cross tolerance relationship for barbiturates
tolerance generalises to benzodiazepines and alcohol
what is the cross tolerance relationship for benzodiazepines
generalisation to alcohol, but only PARTIAL generalisation to barbiturates
what is the best way to stop benzodiazepine use
gradual dose reduction over an 8-12 week period
which two subjective effects of benzodiazepines show tolerance in those who take them for anxiety
feelings of sedation and confusion
what is characteristic of sedative hypnotic withdrawal
tremors, delirium, cramps, convulsions in high dose
things like anxiety, panic, muscle spasms, in low dose
generally things that reflect an increase in activity (opponent process)
ALSO NOTE THAT LOW DOSE WITHDRAWAL OCCURS IN CYCLES OVER A LONG PERIOD OF TIME it is cyclitic
