Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pharmacology > Barbiturates > Flashcards

Barbiturates Flashcards

1
Q

barbs in bottle vs body

A

alkaline in bottle

acidic in body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

barbs preparation, pH, storage, potent isomer

A

sodium salt preparation
highly alkaline, bacteriostatic in bottle
stable/sterile for 6 days
levo isomer is potent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

barbs are derived from:

A

urea + malonic acid = barbituric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

barbs substitutions

A

carbon 2 & 5 substitutions have sedative, hypnotic properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

barbs branched chain @ 5

A

increased hypnotic activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

barbs phenyl group @ 5

A

increased anticonvulsant activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

barbs methyl radical group

A

increased convulsants (methohexital)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

barb sulfuration

A

fat soluble, short duration, rapid onset, increased potency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

barb chain length and potency

A

long branched chain is more potent than straight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

barb isomer comparisons

A

levo is 2x more potent than dextro isomer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

barb mixture availability

A

only available as racemic mixture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

barb w/ oxygen @ #2 name

A

oxybarbiturate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

barb with sulfur @ #2 name

A

thiobarbiturate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

barbiturate relative potency

A

thiopental = 1
thiamylal (surital) = 1.1
methohexital (brevital) = 2.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

barb mechanism of action

A

enhance GABAa activity
decrease transmission of sympathetic ganglia = hypotension
mimics GABA at receptor
decreases post synapse membrane sensitivity to aCh - some muscle relaxation, not surgical depth
depresses reticular activating system = sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

barbs pharmacokinetics

A 
rapid onset
rapid redistribution - will wake up in 5-7 minutes
extensive metabolism
70-85% protein bound
blood fat partition = 11
pK = 7.6
17
Q

barb metabolism

A

oxybarbiturates = hepatic only
thiobarbiturates = hepatic and extra hepatic
side chain oxydation at carbon 5 to carboxylic acid
desulfuration, hydrolysis opens ring
renal excretion
heavy hepatic enzyme inducers!

18
Q

Barb elimination T1/2

A

thiopental - 11.6 hrs
prolonged in pregnancy due to increased protein binding
methohexital - 3.9 hrs

19
Q

barb CNS effects on LOC

A

decrease LOC, CMRO2, CBF, ICP

can produce isoelectric eeg

20
Q

barb CNS excitatory effects

A

paradoxical excitement

methohexital - myoclonus and hiccups

21
Q

barb CNS protection

A

very good cerebral protection

22
Q

barb SSEP monitoring

A

barbs do not affect sensory output from spinal cord

23
Q

barb and pain threshold

A

small doses can cause anti-analgesia

24
Q

barb skeletal muscle relaxation/IOP

A

no skeletal muscle relaxation

decreased IOP

25
Q

barb CV effects

A

decrease SNS, so decrease PVR, preload
decrease SBP, increase HR
minimal myocardial depression

26
Q

barb and trauma

A

DO NOT GIVE
if SNS is not intact, hypovolemic, will see significant decrease in BP and contractility
histamine release with rapid IV push, further decreases SBP
minimal effect with PO barbs

27
Q

barb resp effects

A

dose dependent depression of medullary and pontine ventilatory centers (CNS)
decreased ventilatory response to hypoxia, hypercarbia
apnea
incomplete depression of laryngeal and cough reflex

28
Q

stage 2 of induction**

A

excitatory stage with laryngospasm, bronchospasm when dose is not large enough

29
Q

Which barb has most potent hepatic enzyme inducer

A

phenobarbital

30
Q

barb increases metabolism of what?

A 
oral anticoagulants
phenytoin
TCAs
corticosteroids
Vit k
31
Q

barb and heme

A

accelerates production of heme by stimulation of D aminolevulinic acid synthetase

32
Q

barbs and thrombosis, placenta

A

increases venous thrombosis

readily crosses placenta

33
Q

barbs and pts with siezures

A

metabolize drug 2x faster, (especially muscle relaxants)

34
Q

barbs and tolerance

A

enhances own metabolism, increases tolerance

35
Q

barb allergies

A

1:30,000, high anaphylaxis mortality

36
Q

barb dosing

A

Thiopental 3-5 mg/kg IV, decrease with age/pregancy, increase with infant, peds
Methohexital 1-2 mg/kg IV; 20-30 mg/kg peds
duration of single IV induction: 5-8 minutes due to rapid redistribution

37
Q

what not to mix with barbs

A 
opioids, catechols, NMBs, midazolam
pancuronium
vecuronium
atracurium
alfentanil
sufentanil
midazolam
LR (too acidic)
38
Q

barbs and arterial injection

A 
immediate vasoconstriction, pain
dilute w/ NS
phenoxybenzamine
heparin
brachial plexus block
papaverine 40-80mg in 10-20ml NS or 5-10ml lido
39
Q

barbs and prophyria

A

DO NOT GIVE BARBS TO PATIENTS WITH PROPHYRIA

Pharmacology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions