benzodiazepines Flashcards
trade name of midazolam
versed
how is midazolam supplied
5mg/mL
1mg/mL
MOA of midazolam
binds to stereospecific benzodiazepine receptors on the postsynaptic GABA neuron at several sites within the central nervous system
limbic system
reticular formation
enhancement of the inhibitory effect of GABA on neuronal excitability results by increased neuronal membrane permeability to chloride ions
this shift in chloride ions results in hyper polarization (less excitable state)
stabilization
uses of midazolam
preoperative sedation
moderate sedation prior to iagnostic or radiographic procedures
ICU sedation
induction and maintenance of general anesthesia
what receptor does midazolam bind to?
GABA
where does midazolam work?
CNS
limbic system
reticular formation
what type of receptor is GABA
inhibitory
what ion is affected by midazolam?
Cl
what does the chloride shift due to midazolam result in?
hyperpolarization
less excitable state
stabilization
dose of midazolam IM
0.07 - 0.08 mg/kg 30-60 minues prior to surgery
what is a typical IM dose of midazolam?
5 mg
IV dose of midazolam
0.01-0.03 mg/kg
q5 minues
to affect
max dose of IV midazolam
0.1-0.2 mg/kg
7 mg-14 mg for a 70 kg pt
how is dosage affected for midazolam if the patient is unpremeditated vs. premedicated
premeditated dose much smaller
pre- 0.05-0.2
non-pre 0.3-0.35 mg/kg
dose of maintenance of midazolam
0.05 mg/kg as needed
continuous infusion of midazolam dose
- 015-0.06 mg/kg/hour
0. 25-1 mcg/kg/minute
who gets oral midazolam
peds
oral, rectal, intranasal
onset of IM midazolam
~15 minutes
onset of IV midazolam
3-5 minutes
onset of of oral midazolam
10-20 minutes
onset of intranasal midazolam
4-8 minutes peds
peak of IM midazolam
0.5-1 hour
duration of IM midazolam
6 hours
mean 2 hours
IV single dose of midazolam duration
less than 2 hours
dose dependent
how long is midazolam’s duration with cirrhosis
6 hours
metabolism of midazolam
extensively hepatic
CYP3A4
how much of midazolam is transformed to its active metabolite
60-70%
what is midazolam’s active metabolite
1-hydrozymidazolam
half life or midazolam
2-6 hours
what conditions prolong midazolam’s half life
cirrhosis CHF obesity renal failure- accumulation of active metabolites = prolonged sedation elderly