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Flashcards in Midazolam Deck (32):
1

What is the trade name of Midazolam?

Versed

2

What is the drug classification of Midazolam?

Benzodiazepine

3

What are the effects of Midazolam?

Anxiolysis
Sedation
Anterograde Amnesia
Anticonvulsant
Skeletal muscle relaxation effects

4

What are the clinical uses of Midazolam?

-used in preop medication and conscious sedation
-induction and maintenance of anesthesia
-icu sedation
-office based anesthesia settings
-unlabeled/investigational use for anxiety and status epilepticus

5

What is the MOA of Midazolam?

-produces effects by facilitating the action of GABA, which is the principle inhibitory neurotransmitter of the CNS
-does not activate the receptor but instead enhances the affinity of the GABA receptor for GABAa
-this causes enhanced opening of chloride channels which hyperpolarizes the postsynaptic cell membrane, rendering it more resistant to excitation

6

How is Midazolam metabolized? What are the metabolites?

-rapidly metabolized by Hepatic CYP450 enzymes to active and inactive metabolites
-1-hydroxymidazolam
-4-hydroxymidazolam

7

What is the principle metabolite of Midazolam? How potent is it? How is it eliminated?

1-hydroxymidazolam, which has 1/2 the activity of midazolam
-it is conjugated to 1-hydroxymidazolam glucuronide and cleared by the kidneys

8

Does renal failure alter Midazolam?

E 1/2 time, Vd, and clearance are NOT altered by renal failure

9

Is Midazolam lipid soluble or water soluble in the body? What does this mean?

HIGHLY lipid soluble with rapid redistribution from to inactive tissues

10

What is the onset of action of Midazolam?

30-60 seconds

11

What is the time to Peak of Midazolam?

3- 5 minutes

12

What is the IV DOA of Midazolam? IM?

15 - 80 minutes IV
up to 6 hours IM

13

What is the E 1/2 time of Midazolam? What would prolong this?

1 - 4 hours (Dr. E says 1 - 6.5hrs)
prolonged in: elderly, cirrhosis, CHF, obesity

14

What is the Vd of Midazolam?

1 - 1.5 L/ kg

15

Is Midazolam protein bound?

94% protein bound!

16

What are the CNS effects of Midazolam?

-Paradoxical excitement...EH not really/ RARE
-Decreases CBF and CMRO2
-Does NOT produce isoelectric EEG
-Preserves cerebrovascular response to CO2
-Does NOT attenuate ICP response to laryngoscopy
-Potent Anticonvulsant and Amnestic!!!!!!!

17

What are the respiratory effects of Midazolam?

-Respiratory depression
-Produces dose dependent decrease in Ventilation
-Hypoxemia and hypoventilation enhanced in presence of opioid
-Depresses reflex deglutition (swallowing)
-CO2 response curve FLATTENS- does NOT shift
-transient apnea may occur after large doses

18

What are the CV effects of Midazolam?

-Decreases SVR at induction dosage, BP subsequently decreases
-CO unchanged
-does NOT attenuate SNS response to laryngoscopy

19

What are the contraindications to the use of Midazolam?

-Pregnancy
-Narrow angle glaucoma

20

What drugs slow the metabolism of Midazolam?

-drugs that inhibit CYP450!!!!
-Cimetidine
-Erythromycin
-CCBs
-Antifungals

21

What drugs enhance the metabolism of Midazolam?

-drugs that induce CYP450
-Carbamazepine
-Phenobarbitol
-Phenytoin

22

What drug inhibits hepatic clearance of Midazolam?

Fentanyl inhibits hepatic clearance of midazolam when administered during GA

23

What is the Premedication/ Sedation dosage of Midazolam IV?

0.04 - 0.08 mg/kg IV/IM OR
0.5 - 5 mg IV/IM carefully titrated
(Dr E says 1 - 2.5 mg IV, can give as high as 5mg, as needed)

24

What is the Induction dose of Midazolam?

0.05 - 0.35 mg/kg IV (Dr. E says 0.1 - 0.2 mg/kg over 30 - 60 sec)

25

What is the maintenance dose of Midazolam?

0.05 mg/kg PRN of 1 mcg/kg/min infusion

26

What should you decrease the dosage by if narcotics or other CNS depressants are used?

30%

27

IS Midazolam water-soluble or lipid soluble in solution?

WATER-SOLUBLE- available in an acidified solution which produces minimal irritation after IM or IV injection

28

What is the competitive antagonist of Midazolam?

Flumenazil!

29

What is the pregnancy category of Midazolam?

D

30

What is Midzolams potency compared to Diazepam?

2-3x potency of Diazepam (miller says 3-6)...

31

What is the time to effect site equilibration of Diazepam?

0.9 - 5.6 minutes

32

What is the premedication/pediatric PO dosages for Midazolam?

0.5 mg/kg PO (max po dose for peds: 20mg)