CNSDepressants Flashcards
CNS depressants have __ effect (2)
sedative
hypnotic
CNS depressants are __ dependent
dose
CNS depressants are unique in that they augment __
and/or
inhibit __
GABA inhibition
glutamate excitation
sedative drugs are useful for
anxiety d.o
hypnotic drugs are useful for
onset and maintenance of sleep → insomnia
GABA binds to receptor and opens __ channels,
which cause __
Cl
decreased excitability
3 CNS depressants to know
benzos
barbituates
ethanol
which CNS depressant binds to alpha subunit receptors and requires presence of GABA for effect
benzos
which CNS depressant binds directly to Cl channel at high doses and does not require GABA
barbituates
at low doses, barbituates have similar action to
benzos
ethanol has similar action to
barbituates
z drugs (sleep drugs) bind to the same site as
benzos (alpha subunit)
what drug is an antagonist to z drugs and is used in the tx of benzo toxicity
flumazenil
is flumazenil effective for BARB and ethanol toxicity
no
uses of benzos
anxiolysis → sedation
anticonvulsant
muscle relaxation
hypnosis
anesthesia
what 2 drugs inhibit sz activity in cortical neurons at higher doses
benzos
barbituates
drug of choice for status epilepticus
benzo → diazepam
all benzos act as __ drugs
hypnosis → sleep
__ are used to induce anesthesia
and benzos are used as __ in anesthesia
barbituates
adjuncts (amnesia-like)
are benzos capable of anesthesia induction
no!
what barbituate is used for anesthesia induction
thiopental
bad s.e of benzos
tolerance
psychological dependence
withdrawal
physical dependence is really only a concern w. __ benzo use
chronic
sx of benzo withdrawal
nausea
fatigue
tachycardia
insomnia
dpn
wt loss
s.e of benzos w. short half lives, benzos, and etoh
increased excitability →
anxiety
tremors
hyperreflexia
convulsions
most rapid benzos
diazepam
alprazolam
clorazepate
triazolam
IM benzo
lorazepam
benzo w. poor IM bioavailability
diazepam
distribution of benzos is __
and can terminate CNS effects of single dose
rapid
benzos that cause daytime sedation dt longer half lives
diazepam
chlordiazepoxide
flurazepam
benzos w. rapid conjugation and short lived effects
alprazolam
triazolam
which 2 benzos are metabolized directly to inactive glucoronides
lorazepam
oxazepam
which 2 benzos are good for elderly and impaired hepatic fxn dt shorter half lives and less residual effects
lorazepam
oxazepam
__ is a major factor in benzo metabolism (2)
age
hepatic fxn
esp phase I rxns
why do barbituates have declining use
potent CYP450 inducers
many ddi
do benzos induce CYP450 enzymes
no
change in Cp is possible when benzos are given w,
cyp450 inducers → barbituates
mc adr related to benzos
CNS dpn →
daytime sedation
performance impairment
rebound insomnia
adr of benzos are mc w.
higher doses
longer half lives
CNS are more likely in
older pt’s
what causes rebound insomnia
abrupt termination of benzos
two drugs w. additive CNS dpn effects when mixed w. benzos
etoh
opioid analgesics
anterograde amnesia is common w. drugs that
enhance GABA neuronal fxn → depress glutamate
beneficial use of anterograde amnesia
uncomfortable procedures
criminal use of anterograde amnesia effect
date rape drug → flunitrazepam (rohypnol)
benzos are a class __ drug
IV
controlled substance
risk for dependence
moa for flumazenil (romazicon)
specific benzo antagonist
clinical use of flumazenil
reverses sedative effects of benzos →
od tx
hasten recovery following anesthesia
is flumazenil effective for barb or etoh od
nope!
just benzos
major difference btw z drugs and benzos
z drugs only target alpha receptors
