Benzos Flashcards
why are barbiturates more toxic than benzos
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
predisposing factors for benzo od
age
hepatic impairment
COPD
cns effects
mild - drosy, lethargy within 30min
moderate -slurred speech, amnesia, ataxia
severe - stupor or coma (hypothermia, hyporeflexia, miosis)
rare paradoxical reactions - agitation, aggression, condusion
respiratory effects
resp depression parallels cns depression, but not always
hypoventilation
cardiovascular effects
non ein benzo and z drugs
postural hypotension or bradycardia in high risk
cardiovascular collapse rare
unholy trinity
benzos
opioids
skeletal muscle relaxant
possible risk factors
elderly on opiods benzo niave high dose copd emotional distress undetected depression/suicidal
treatment of od
supportive measures
activated charcoal for poly drug overdose
urinary alkalinization for barbiturates
hemodialysis doesnt work??
antidote
flumazenil
flumazenil moa
competitive antagonist of bz receptor
reverses bzd induced cns depression but can induce withdrawal
when do you use flumazenil
benzo naive pts with benzo only overdose
dose of flumazenil
1.-.2mg iv over 20sec
subsequent doses of 0.3mg and 0,5mg at 1 min interval up to 3mg total
very short acting
flumazenil contraindication
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
ideal scenario for flumazenil
pure benzo overdose in nontolerant individual who has CNS depression, normal vital signs normal ECG normal neurological exam
chronic use issues
tolerance and dependence during continuous use and withdrawal after cessation
pharmacotherapy substitutions
longer acting beno pregabalin carbamazepine melatonin flumazenil patch
treating benzo dependency
gradual dose reduciton + behavioral or psychological interventions
swithc agent
gradual dose reduction regimen
decreased dose 10-25% every 1-2 weeks
usually dont have to switch to long acting benzo
short half life benzos
increased tolerance and dependence
midazolam
triazolam
long acting benzos
diazepam
secreted in breast milk
managing benzo od
protect airways, assist ventilation
treat coma - glucose, thiamin, naloxone
treat hypotension - fluids, epinephrine
treat hypothermia - warm them up
benzo tolerance
tolerance to sedative and antianxiety effect
cross tolerance - alcohol, barbiturate
chronic toxicity of benzo
no organ damamge
tolerance, dependence, withdrawal
lower dependence than other sedative agents
benzo withdrawal symptoms
mild: anxiety, insomnia, tremor
major: seizure, psychosis, delirium
