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Anesthesia Pharm > Benzos > Flashcards

Flashcards in Benzos Deck (23)
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1
Q

Indications for Benzos

A

Component of a well balanced anesthesia

DT mananagement

Rarely for induction

2
Q

Where are GABA receptors found?

A

cell membrane

  • ligand gated ion channel
3
Q

major inhibitory receptor of the mamallian brain?

A

GABA

stereospecific and saturable

4
Q

What happens to GABAA receptor occupation?

A

* increases frequency of opening

5
Q

What is unqie about Midazolam?

A
  • It is a water soluble benzo with a imidazole ring
    • The ring remains OPEN at ph <4.0
    • The ring CLOSES AT ph > 4.0
6
Q

When would mental function return after the administration of Midaz?

A

4 hours after administration

7
Q

How is Midazolam metabolized?

is there a metabolite?

A

Hydroxylation by microsomal oxidative mechanism

–> CYP3A4, CYP3A5

Metabolite: alpha- hydroxymidazolam metabolite–> weakly active

8
Q

What affects the pharmacokinetics of Midazolam

A

age, obesity, hepatic cirrhosis

9
Q

Hepatic clearance is ___X more than lorazepam and __x more than diazepam

A
  • 5X
  • 10X
10
Q

is the VD of Midaz affected by renal clearance?

A

It is not.

But it is affected by CYP and hepatic blood flow [intermediate hepatic ratio]

11
Q

Diazepam is stored in ___

extensively bound to ___

A

propylene glycol and sodium benzate

extensively bound to plasma proteins [albumin]

highly lipid soluble

12
Q

What is responsible to Diazepam’s prolonged effects?

A

Desmethyldiazepam metabolite is responsible for prolonged effect.

Characteristics return of drowsiness after 6-8 hours [BIPHASIC]

13
Q

Characteristics: Lorazepam

A
14
Q

MOA: of Flumazenil

A
  • minimal agonist activity
  • effects are weak

- competitive antagonization

15
Q

What are the alpha units and what are they responsible for?

A

alpha 1 = sedation, amnesia, anticonvulsant

alpha 2 = skeletal muscle relaxation, spinal cord mediated

alpha 5 = sedation, amnesia, antoconvulsant

16
Q

What is the effect of benzos on ICP?

A

NONE

- ANTICONVULSANT

- ANXIOLISIS

- ANTISPASMODIC [spinally mediated]

- Anterograde amnesia [1 - 2 hours]

17
Q

GABA Receptor density

A
18
Q

Know your EEGs

Apha waves?

beta waves?

Theta waves?

Delta

can benzos preserve burst supression?

A
  • benzos decrease alpha waves and accentuate beta waves
  • yes. benzos can give burst supression but not isoelectric
19
Q

Benzos: Ventilation

A

decrease in ventilation [tv and mv] = apnea in induction doses

pcO2 response curve - FLAT

20
Q

Sedation Dose with Benzos

A
21
Q

SE: Benzos

A
22
Q

BENZOS CONTRAINDICATION

A

TETRATOGENIC

23
Q

Diazepam dose

A