2-sleep aids Flashcards
what is a hyptonic
a drug that is used to treat insomnia
what was dangerous about old hypnotic agents
narrow therapeutic windows
what 5 signals are involved in the sleep wake cycle
histamine GABA Adenosine Melatonin Orexin
how do drugs affect histamine in the sleep wake cycle
block histamine to make you drowzy
but not a great quality sleep
how do drugs affect GABA in the sleep wake cycle
boost GABA to decrease neuronal excitability
most common
how do drugs affect adenosine in the sleep wake cycle
neuromodulator, caffeine blocks the effect of adenosine
lots of side effects, cardiac
what is adenosine in the sleep wake cycle
neuromodulator (changes how other neurotransmitters work)
how do drugs affect melatonin in the sleep wake cycle
they do more stuff for circadian rhythm
how do drugs affect orexin in the sleep wake cycle
drug blocks the peptide orexin which is made in the hypothalamus and is involved in sleep wake cycling
which stages of sleep do benzodiazepines affect
REM sleep suppressants
increase stage 2
what happens to REM sleep as the night progresses
REM sleep increases
where are sleep spindles and K complexes found
stage 2
which stages are the deep sleep
3 and 4
how well do hypnotics replicate normal sleep cycles
not perfectly
what did chloral hydrate (chlorinated ethanol) do and why was it dangerous
“knock-our drops” but very dangerous
why is alcohol bad as a sleep aid
it doesn’t get you into deep sleep, its just bad for you okay
how do barbiturates and benzodiazepines work (What is the target)
positive allosteric modulators of GABA-A receptors
what happens when you potentiate the agonist effects of GABA
more Cl- ions go through, it decreases neuronal excitability
what is pentobarbital
a barbiturate
how did pentobarbital work
allosteric modulator that increases the length of time the channel stays open in the presence of GABA
what happens with pentobarbital at high concentrations
it directly opens the channel even when GABA isnt there!
why is pentobarbital lethal when combined with alcohol
both of them increase Cl- to pass through, often death by asphyxiation
what is triazolam (halcion)
benzodiazepine
why is triazolam safer than pentobarbital
at high doses, it does not directly activate . the channel
what does triazolam do
allosteric modulator that increases the frequency of channel openings in the presence of GABA
so why are benzodiazepines and barbiturates different if they bind at the same site
they dont bind at the same site. barbs bind lower
benzos bind closer to the top and closer to where gaba binds
why are benzos good for anxiety
because it can decrease neuronal firing
what receptors are bezos selective for
GABA-A
highly selective
which receptors are benzos not selective for
no affinity for glycine (even tho its super similar) and none of glutamate LGICs
why are benzos only used in acute emergency situations IV for seizures
rapid development of tolerance
what is the ceiling effect
BZs do not directly effect the channel at high doses, so they is a plateau before there are severe dangerous side effects
(barbs have direct effects on the channel, creating severe effects,even death)
what is the diazepam half life
long, 30-56 hours
what is nordazepam half life
7 days
why are benzos not great for sleep
super long half life, it gives daytime impairment
what is triazolam (Halcion)
what half life
hypnotic, 2 hours
what is the active metabolite of triazolam
none
what are the side effects of traizolam
high doses cause daytime memory impairment and some violence
why isnt triazolam good for time time or early waking
because short half life, only helps with falling asleep
why are BZ bad for memory
they are not selective within GABA-A, so they affect hippocampal receptors in memory formation and storage, and also it decreases REM
what happens once you stop using benzos to sleep
you get a really bad rebound insomnia
addiction and dependence
why are Benzos good for surgeries
cause it reduces memory and helps you forget what happened
whats so special about Z-drugs
they have short half lives and bind at the GABA-A
why are there different side effects to benzos
may have different selectivity towards specific GABA-A receptors so diff symptoms and less REM suppression so less REM rebound
what does suvorexant (belsomra) do
antagonises orexin receptor to promote sleep onset and maintenance
what do orexins do
peptides that are important for signal control of the sleep/wake cycle
what does high orexins cause
wake
what does low orexins cause
seep
what happens when you block orexin receptors
promotes sleep
where are orexins made and what types
A and B are made in hypothalamus, secreted in the neurons there
how powerful is suvorexant
not very, studies show it may help you sleep 6mins more at night
