Anesthesia Pharm Test 1 Part 2 Flashcards
what are the most popular benzos for IV anesthetics
- diazepam 2. lorazepam 3. midazolam
structure of benzos
heterocyclic ring structure with benzene & diazepene ring
_________________ is the one benzodiazepine that has a imidazole ring as primary structure allowing it to dissolve in aqueous solutions
midazolam
midazolam undergoes conformational change once in the blood stream making it more _________________
lipophillic
_________________ rose to popularity for their anterograde amnesia, anxiolytic, and sedative effects with miminal s/e
benzodiazepines
which benzo has the greatest incidence of causing phlebitis
diazepam
benzos are highly _________________, and ___________________ protein bound
lipophilic; highly
metabolism of benzodiazepines
liver via CYP450
excretion of bz
renal
MOA of benzodiazepines
bind to allosteric site of GABA-A receptor in the cortex and brainstem causing Cl- channels to open more frequently
CNS effects of benzos
- dose dependent CNS effect 2. small amount of centrally mediated muscle relaxation 3. higher dose = sedation 4. lower dose = anxiolytic
CV effects of benzo
- induction dose –> decrease of SVR and BP 2. otherwise HD stable
respiratory effects of benzos
- depress upper airway reflexes (esp with other sed/opioids) 2. caution in those with OSA/compromised airway
benzos are primarily used for what
pre-medication for sedation
which drug is primarily used as pre-medication for sedation
midazolam
what drug is typically used as a first line therapy for status epilepticus
lorazepam
for peds, if you give midazolam pre-procedure you give ________ mg/kg via __________ route, _________ min prior to procedure
0.5; p.o; 30
s/e of benzos
- irritation and phlebitis 2. delirium in elderly and critically ill
_______________ is a benzodiazepine reversal agent
flumazenil
MOA of flumazenil
competitive antagonist with high affinity to the “benzo” receptor site on the GABA-A receptor
dose of flumazenil
administer 0.2 mg then redose at 0.1 mg as needed
typically ________ mg of flumazenil is enough to reverse sedation, but you may need ___________ mg to reverse bz toxicity
1; 3
flumazenil will act within __________ min and has a duration of action of __________ min
1-2; 45-90
c/i of flumazenil
- seizure d/o 2. Bz dependance
T/F: flumazenil has a short 1/2 when compared to bz
TRUE
propofol “SHARP LAD”
- stimulates GABA 2. hypotension 3. antiemetic qualities 4. respiratory depression 5. pain on injection 6. lipid soluble 7. avoid in allergies 8. decreases CBF and ICP
what is the most widely used IV anesthetic drug
propofol
T/F: propofol is recognized as “essential medicine”
TRUE
what feature of propofol allows for “fast-on, fast-off”
highly lipophillic structure
propofol is formulated as an emulsion of ?
soybean oil, glycerol, and egg lecithin
all vials of propofol are single use and syringes should be discarded after __________ hours, and vials after __________ hours
6; 12
propofol formulation adds what preservatives to reduce the infection risk in the vial?
ETDA + sodium metabisulfite or benzyl alcohol
propofol is metabolized in the liver by _____________, _____________, & ______________
CYP2B6; UGTHP4; CYP2C6
plasma clearance of propofol is high and exceeds hepatic blood flow, therefore ____________________ metabolism is vital
extra-hepatic sites of
what are the extrahepatic sites of metabolism for propofol
lungs and kidneys
MOA of propofol
allosterically binds to GABA-A in brainstem and cortex increases the receptor affinity for GABA (thus increasing more GABA to the bind to the receptors)
which IV anesthetic can cause a total isoelectric EEG with higher dose
propofol
CNS effects of propofol
- dose dependent anxiolysis 2. sedation 3. amnesia 4. lowers CMRO2, ICP, and CPP 5. aniemetic effect 6. anti-epileptic effect
__________________ is used as neuroprotective agent when combined with other agents
propofol
CV effects of propofol
induction –> decrease BP, MAP, and CO
respiratory effects of propofol
- bronchodilatory 2. dose dependent apnea 3. decreases TV and response to hypoxia/hypercarbia
T/F: in diprivan there is a preservative than can predispose pts to bronchospasm
false; only in generic propofol is there a preservative that predisposes to bronchospasm, not diprivan
uses of propofol
- induction of anesthesia 2. TIVA 3. sedation 4. PONV
induction dose of propofol for adults
1-2.5 mg/kg
induction dose of propofol in children
2.5-3.5 mg/kg
infusion rate of propofol for TIVA
100-200 mcg/kg/min
infusion rate of propofol for sedation
25-75 mcg/kg/min
dose of propofol infusion for PONV prevention
10-30 mcg/kg/min
s/e of propofol
- pain on injection 2. allergic response 2/2 egg lecithin 3. PRIS
PRIS is seen in icu patients on propofol at dose of > ________ mg/kg/hr for more than ___________ hours
4; 48
