sedative hypontic drugs Flashcards Preview

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Flashcards in sedative hypontic drugs Deck (38)
1

barbituate vs benzos dose response relationship curves

barb: linear

benzo: non-linear (safer)

2

benzodiazepines MOA

bind GABA(a) - between alpha and gamma subunit (BZ1 and BZ2)

GABA(a) is a chloride channel - activated by inhibitory GABA

increase in FREQUENCY of chloride influx

allosteric enhancement of GABA effect

3

benzo receptor agonist, antagonist, inverse agonist

agonist: **positive allosteric modulators

antagonist: flumazenil (blocks benzo action)

inverse agonist: negative allosteric modulators of GABA (oppose GABA - cause anxiety and seizures) - only experimental drugs

4

benzo actions

reduce anxiety
sedative and hypnotic actions
anticonvulsant
muscle relaxant
anesthesia

5

benzo PK

lipophilic
various duration of actions
short, intermediate, long acting

6

diazepam: short, intermed, long acting?

long 1 -3 days

7

flurazepam: short, intermed, long acting?

long 1 - 3 days

8

alprazolam: short, intermed, long acting?

intermediate: 10-20 hours

9

lorazepam: short, intermed, long acting?

intermediate: 10-20 hours

10

temazepam: short, intermed, long acting?

intermediate: 10-20 horus

11

oxazepam: short, intermed, long acting?

short 3-8 hours

12

triazolam: short, intermed, long acting?

short 3-8 hours

13

all benzo's undergo phase 1 by CYP3A4 except which 3 drugs

oxazepam
lorazepam
temazepam

good to use in pt with poor liver function or those with poor P450 function

14

desmethyldiazepam

t 1/2 of >40 hours = active metabolite of several benzo's

metabolized into oxazepam

15

flurazepam

oxidized by liver enzymes to active metabolites with long half lifes (30-100 hours)

16

diazepam use

muscular disorder

17

benzo use for seizures

clonazepam

lorazepam and diazepam: status epilepticus

18

tx drug withdrawal

diazepam
oxazepam

for etoh withdrawal

19

benzo use for sleep disorders

flurazepam - long acting
temazepam - intermediate
triazolam - short

20

benzo AE

drowsiness/confusion
ataxia
cognitive impariment

pysch effects = irritable, hostile, paranoia

dependence - withdrawal = confusion, agitation, insomnia

21

flumazenil

only benzo receptor antagonist

reverses CNS depressant effects of benzo OD

22

flumazenil PK

rapid onset, short duration (half life 1 hour)

for OD tx = keep giving flumazenil to maintain reversal

may precipitate withdrawal

23

barbituates

less used b/c AE - tolerance, P450 inducers, coma

24

barbituate MOA

(not as selective as benzo's)

GABA(a) receptors - enhance transmission

increase DURATION of opening of chloride channels

also block glutamate receptors and sodium channels

25

barbituate dose vs action

low - sedation

high - hypnosis

-- anesthesia, coma, death

26

barbituate action

resp depression: suppress hypoxic and chemoreceptor response to CO2

induces P540

anesthesia: thiopental

anticonvulsant: phenobarbital

27

barbituate AE

drowsiness
paradoxical excitement
hypersensitivity
resp depression

*may worsen pain
*severe withdrawal

28

zolpidem

non-benzo benzodiazepine receptor agonist

short duration - 1.5 - 3.5 hr half life

use: short term tx of insomnia

29

zaleplon

non-benzo benzodiazepine receptor agonist

half life - 1 hour

use: short term insomnia tx

30

eszopliclone

non-benzo benzodiazepine receptor agonist

s-enantiomer of zopiclone

tx: insomnia - decreases sleep latency AND improves sleep maintenance

half life - 6 hours (longer half life of z drugs)

31

non-benzo benzodiazepine receptor agonist

act only at BZ1 subtype receptor

hypnotic
minimal muscle relaxant and anticonvuslant effects
little tolerance
dec AE

32

5HT1a partial agonist

buspirone

33

buspirone

5HT1a partial agonist

only anxiolytic effects (no hypnotic, anticonvulsant, relaxant)

use= anxiety disorders

onset - 2 to 3 weeks (MOA analogous to antidepressants)

34

buspirone advantages

less psychomotor impairment
no drug interactions with EtOH, benzos, sedatives

no rebound anxiety or withdrawal signs

no dependence

35

ramelteon

melatonin receptor agonist
at MT1 and MT2 receptors

tx: insomnia with difficult sleep onset

36

hydroxyzine

antihistamine + antiemetic activity

sx relief of anxiety

37

propanolol

performance anxiety

clonidine may also help with autonomic expression of anxiety

38

other classes...

diphenhydramine
doxylamine

nonprescrip anti-histamines = tx mild insomnia