Benzos

Question 1

Indications for Benzos

Answer 1

Component of a well balanced anesthesia

DT mananagement

Rarely for induction

Question 2

Where are GABA receptors found?

Answer 2

cell membrane

• ligand gated ion channel

Question 3

major inhibitory receptor of the mamallian brain?

Answer 3

GABA

stereospecific and saturable

Question 4

What happens to GABA_A receptor occupation?

Answer 4

* increases frequency of opening

Question 5

What is unqie about Midazolam?

Answer 5

• 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

Question 6

When would mental function return after the administration of Midaz?

Answer 6

4 hours after administration

Question 7

How is Midazolam metabolized?

is there a metabolite?

Answer 7

Hydroxylation by microsomal oxidative mechanism

–> CYP3A4, CYP3A5

Metabolite: alpha- hydroxymidazolam metabolite–> weakly active

Question 8

What affects the pharmacokinetics of Midazolam

Answer 8

age, obesity, hepatic cirrhosis

Question 9

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

Answer 9

• 5X
• 10X

Question 10

is the VD of Midaz affected by renal clearance?

Answer 10

It is not.

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

Question 11

Diazepam is stored in ___

extensively bound to ___

Answer 11

propylene glycol and sodium benzate

extensively bound to plasma proteins [albumin]

highly lipid soluble

Question 12

What is responsible to Diazepam’s prolonged effects?

Answer 12

Desmethyldiazepam metabolite is responsible for prolonged effect.

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

Question 13

Characteristics: Lorazepam

Answer 13

Question 14

MOA: of Flumazenil

Answer 14

• minimal agonist activity
• effects are weak

- competitive antagonization

Question 15

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

Answer 15

alpha 1 = sedation, amnesia, anticonvulsant

alpha 2 = skeletal muscle relaxation, spinal cord mediated

alpha 5 = sedation, amnesia, antoconvulsant

Question 16

What is the effect of benzos on ICP?

Answer 16

NONE

- ANTICONVULSANT

- ANXIOLISIS

- ANTISPASMODIC [spinally mediated]

- Anterograde amnesia [1 - 2 hours]

Question 17

GABA Receptor density

Answer 17

Question 18

Know your EEGs

Apha waves?

beta waves?

Theta waves?

Delta

can benzos preserve burst supression?

Answer 18

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

Question 19

Benzos: Ventilation

Answer 19

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

pcO2 response curve - FLAT

Question 20

Sedation Dose with Benzos

Answer 20

Question 21

SE: Benzos

Answer 21

Question 22

BENZOS CONTRAINDICATION

Answer 22

TETRATOGENIC

Question 23

Diazepam dose

Answer 23