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Flashcards in Local Anesthetics Deck (15)
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1

What are the two classes of local anesthetics?

amide and ester type

2

What is the approximate pK of LA?

8-9

3

Are LAs more ionized or less ionized at physiologic pH?

more ionized

4

Where do LA work?

intracellular side of VG Na+ channels

5

How do LA get across the cell membrane?

non-ionized form crosses
non-ionized form is ionized
ionized form is active on VG Na+ channels

6

What is the active form of LA?

ionized

7

What form of LA crosses the membrane?

non-ionized

8

LA work on NA channels at what stages:
-resting
-open
-inactivated

only open and inactivated
more potent on more active neurons

9

Side effect of LA with regards to circulation?

sm. muscle VG Na+ channels also blocked
-->vasodialation
==>faster clearing of drug

10

Why is epinephrine added to more LA preparations?

they cause vasoconstriction

11

Where are ester LA metabolized?

in plasma
pseudocholinesterase

12

Where are amide LA metabolized?

in liver
mixed oxidases

13

What type of LA is more common to produce a hypersensitivity reaction?

ester

14

What is a Bier block?

IV admin of LA with tourniquet

15

Ester is old and needs PT

procaine and
tetracaine are ester LA