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TOXICOLOGY > Benzos > Flashcards

Flashcards in Benzos Deck (24)
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1
Q

why are barbiturates more toxic than benzos

A

barbs allosterically hold channel open so unlimited cna go through
benzos allow greater frquency for ion channel to open so only a certain amount can go through at a time

2
Q

predisposing factors for benzo od

A

age
hepatic impairment
COPD

3
Q

cns effects

A

mild - drosy, lethargy within 30min
moderate -slurred speech, amnesia, ataxia
severe - stupor or coma (hypothermia, hyporeflexia, miosis)
rare paradoxical reactions - agitation, aggression, condusion

4
Q

respiratory effects

A

resp depression parallels cns depression, but not always

hypoventilation

5
Q

cardiovascular effects

A

non ein benzo and z drugs
postural hypotension or bradycardia in high risk
cardiovascular collapse rare

6
Q

unholy trinity

A

benzos
opioids
skeletal muscle relaxant

7
Q

possible risk factors

A
elderly 
on opiods
benzo niave
high dose
copd 
emotional distress 
undetected depression/suicidal
8
Q

treatment of od

A

supportive measures
activated charcoal for poly drug overdose
urinary alkalinization for barbiturates
hemodialysis doesnt work??

9
Q

antidote

A

flumazenil

10
Q

flumazenil moa

A

competitive antagonist of bz receptor

reverses bzd induced cns depression but can induce withdrawal

11
Q

when do you use flumazenil

A

benzo naive pts with benzo only overdose

12
Q

dose of flumazenil

A

1.-.2mg iv over 20sec
subsequent doses of 0.3mg and 0,5mg at 1 min interval up to 3mg total
very short acting

13
Q

flumazenil contraindication

A

physically dependent (withdrawal)
benzo for control of seizure disorder
cardiac arrythmia or high risk of arrhythmia
coingestion of agents causing seizures (TCA)
increased intracranial pressure (seizure risk)
unknown history

14
Q

ideal scenario for flumazenil

A
pure benzo overdose in nontolerant individual who has 
CNS depression, 
normal vital signs
normal ECG
normal neurological exam
15
Q

chronic use issues

A

tolerance and dependence during continuous use and withdrawal after cessation

16
Q

pharmacotherapy substitutions

A
longer acting beno
pregabalin 
carbamazepine
melatonin 
flumazenil patch
17
Q

treating benzo dependency

A

gradual dose reduciton + behavioral or psychological interventions
swithc agent

18
Q

gradual dose reduction regimen

A

decreased dose 10-25% every 1-2 weeks

usually dont have to switch to long acting benzo

19
Q

short half life benzos

A

increased tolerance and dependence
midazolam
triazolam

20
Q

long acting benzos

A

diazepam

secreted in breast milk

21
Q

managing benzo od

A

protect airways, assist ventilation
treat coma - glucose, thiamin, naloxone
treat hypotension - fluids, epinephrine
treat hypothermia - warm them up

22
Q

benzo tolerance

A

tolerance to sedative and antianxiety effect

cross tolerance - alcohol, barbiturate

23
Q

chronic toxicity of benzo

A

no organ damamge
tolerance, dependence, withdrawal
lower dependence than other sedative agents

24
Q

benzo withdrawal symptoms

A

mild: anxiety, insomnia, tremor
major: seizure, psychosis, delirium