Lorazepam Flashcards Preview

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Flashcards in Lorazepam Deck (29):
1

What is the trade name of Lorazepam?

Ativan

2

What is the formal class of Lorazepam?

Benzodiazepine

3

What are the effects of Lorazepam?

Anxiolytic
Sedative
Hypnotic
Amnesiac
Anticonvulsant
Centrally produced muscle relaxant properties

4

What are the clinical uses of Lorazepam?

-Facilitate sedation of patients in ICU, or postop sedation of intubated pt
-more potent sedative and amnestic than midaz and diaz
-limited usefulness for IV induction of anesthesia, IV sedation during regional anesthesia, or use as an anticonvulsant due to its slow onset
-Rapid and reliable for stopping seizures IV or rectally

5

What is the MOA of Lorazepam?

-facilitates the actions of GABA by enhancing the affinity of GABA for the GABAa receptors
-resistance to excitation causes anxiolysis, sedation, anterograde amnesia, alcohol potentiation, and anticonvulsant and skeletal muscle relaxant effects

6

How is Lorazepam metabolized?

Hepatic metabolism: slowly conjugated with glucuronic acid in the liver to form pharmacologically INACTIVE metabolites excreted by the kidneys

7

Does lorazepam have active metabolites?

NO

8

Is lorazepam lipid soluble?

HIGHLY lipid soluble and highly absorbed form the GI tract after oral administration

9

What is different about the onset of action of Lorazepam compared to the other benzos?

-slower onset of action due to realatively LOWER lipid solubility, and therefor slower entrance into the CNS

10

What is the elimination 1/2 time of Lorazepam?

10 - 20 hours

11

What is the duration of action of Lorazepam?

11 - 20 hrs

12

What is the volume of distribution of Lorazepam?

0.8 - 1.3 L/kg

13

Is Lorazepam protein bound?

highly protein bound 80%

14

What are the CNS effects of Lorazepam?

-Reduces CBF by 24% and CMRO2 by 21% with minimal change in ICP
-Decreased motor coordination and impairment of cognitive function when used in combo with other CNS depressant drugs
-fatigue and drowsiness are the most common SE in pt treated chronically

15

What are the respiratory effects of Lorazepam?

-Dose related central respiratory system depression

16

What are other side effects of Lorazepam?

-venous irritation and thrombophlebitis d/t aqueous insolubility
-Decrease adenosine degradation which is an important regulator of cardiac function and gives cardioprotection during MIschemia
-inhibits platelet activation factor induced aggregation, which causes drug-induced inhibition of platelet aggregation

17

What are the contraindications to use of Lorazepam?

Glaucoma

18

What drugs enhance the sedative effects with Lorazepam?

synergistic effect with other CNS depressants decreasing anesthesia required

19

What is the oral dosage of Lorazepam? the max?

50mcg/kg not to exceed 4mg; the maximal plasma concentration is 2-4hr and persists at therapeutic lvls for up to 24-48hrs, with maximal anterograde amnesia lasting up to 6hr

20

What is the IV dose of Lorazepam?

1 - 4mg

21

What is the onset of action of Lorazepam?

1-2min

22

What is the time to peak effect of Lorazepam?

20 - 30 min to peak effect

23

What is the DOA of sedative effects of Lorazepam?

6 - 10 hours

24

What is the antagonist of Lorazepam?

Flumenazil

25

What is different about Lorazepam with respect to metabolism?

less influenced by alterations in hepatic function, age, and other drugs

26

How is Lorazepam prepared?

has propylene glycol as solvent

27

What is special about Lorazepam as an amnestic?

it is the most potent amnestic of the benzos used in anesthetic practice

28

What is different about Lorazepam with regards to lipid solubility?

LOWER/ LESS lipid solubility than Valium so it has a shorter 1/2 life!

29

What is different with regards to the onset of Lorazepams action? what is the peak to plasma [ ]?

SLOW onset limits usefulness (it is the distinguishing feature)
2 hrs to peak plasma [ ]