Local Anesthetics

Question 1

what characteristic of local anesthetics allows them to cross cell membranes

Answer 1

they’re amphipathic- both lipophilic and hydrophilic characteristics

Question 2

are ester linked or amide linked local anesthetics more prone to rapid hydrolysis and inactivation

Answer 2

ester

Question 3

are ester linked or amide linked local anesthetics at high risk for causing hypersensitivity

Answer 3

ester

Question 4

are ester linked or amide linked local anesthetics used more on mucous surfaces

Answer 4

ester

Question 5

what is the mechanism of action of local anesthetics

Answer 5

bind with cytoplasmic receptors and inhibit VGNaC, prolonging the channel in the inactive form

Question 6

do local anesthetics have high affinity for resting, activated, or inactivated VGNaC

Answer 6

inactivated

Question 7

the effects of local anesthetics are pronounced in __ and not in __

Answer 7

in rapidly firing axons
not in resting neurons

Question 8

how many nodes of ranvier are sufficient to induce local anesthesia

Answer 8

2-3

Question 9

does an increase in extracellular calcium increase of decrease the effects of local anesthesia

Answer 9

increase

Question 10

tetrodotoxin comes from __

Answer 10

puffer fish

Question 11

saxitoxin comes from __

Answer 11

algae

Question 12

ciguatoxin comes from __

Answer 12

exotic fish

Question 13

batrachotoxin comes from __

Answer 13

frogs

Question 14

what is the order of blockage between motor, sensory, and autonomic fibers

Answer 14

autonomic first, then sensory and motor

Question 15

what is the order of recovery between motor, sensory, and autonomic fibers

Answer 15

motor, sensory, then autonomics

Question 16

are smaller or larger fibers more sensitive to blockade

Answer 16

small

Question 17

are myelinated or unmyelinated fibers more sensitive to blockade

Answer 17

myelinated

Question 18

what fibers, A/B/C, are affected first due to their response to low concentration of local anesthetic

Answer 18

B

Question 19

what is an example of a differential blockade in which local anesthetics block sensory impulses while sparing motor and proprioception

Answer 19

labor analgesia

Question 20

diffusion of local anesthetics is in the __ (unionized basic or charged) form, which is then converted to the __ (unionized basic or charged) form inside the axon

Answer 20

diffusion= unionized basic
converted to charged

Question 21

what is the relationship between local anesthetic effect and inflammation

Answer 21

inflammation produces lactic acid products. acidification of tissues slows the local anesthetic effectiveness

the anesthetic becomes charged and is unable to penetrate the nerve cell membrane

Question 22

what can be done to eliminate the effect of increased acidity with inflammation when giving a local anesthetic

Answer 22

enhance with sodium bicarbonate to increase the pH

Question 23

amide linked local anesthetics use is cautioned in those with __, __, and those taking __

Answer 23

hepatic disease
congestive heart failure
beta blockers

Question 24

local anesthetics have drug-drug interaction with what 2 classes of drug

Answer 24

alpha 2 agonist
opioids

Question 25

the duration of action of local anesthetics is proportional to ))

Answer 25

the duration of contact with the nerves

Question 26

what can be used to prolong the effect of local anesthetics

Answer 26

vasoconstrictors

Question 27

vasoconstrictors with local anesthetic use is contradicted in procedures involving what body sites

Answer 27

tip of nose feet toes penis fingers

Question 28

what is the effect of local anesthetic use on the CNS

Answer 28

stimulation then depression

Question 29

what is the mechanism of action of cocaine as a local anesthetic

Answer 29

blocks reuptake of NE causes vasoconstriction

Question 30

what local anesthetic is used in the ocular and tracheobronchial regions to reduce bleeding

Answer 30

cocaine

Question 31

is cocaine lipid soluble? does cocaine have a high or low potency?

Answer 31

lipid soluble high potency

Question 32

procaine is a local anesthetic with a lower potency and shorter course of action as compared to cocaine. procaine reduces the effect of what drug class

Answer 32

sulfonamides

Question 33

what local anesthetic is used as an antiarrhythmia and is the drug of choice in ventricular fibrillation following MI

Answer 33

lidocaine

Question 34

in what cases with a vasoconstrictor now be used with a local anesthetic

Answer 34

during cases of arrhythmia, as vasoconstrictors can worsen arrhythmias

Question 35

what local anesthetic is long acting and produces more sensory block and motor block, thus being preferred during labor

Answer 35

Bupivacaine

Question 36

Bupivacaine causes more __ but less __

Answer 36

more cardiotoxicity less nephrotoxicity

Question 37

what local anesthetic has less risk for transient neurologic symptoms

Answer 37

Bupivacaine

Question 38

what local anesthetic should be avoided in pregnancy

Answer 38

Mepivacaine

Question 39

how does Prilocaine differ from lidocaine

Answer 39

it can be used without a vasoconstrictor it's used for IV regional block

Question 40

what 2 drugs make up Eutectic Mixture of LAs (EMLA)

Answer 40

lidocaine Prilocaine

Question 41

Eutectic Mixture of LAs (EMLA) is effective for __ but should not be used for __

Answer 41

effective for procedures involving skin and superficial tissue not effective for mucous membranes or abraded skin

Question 42

where is the local anesthetic injected into with spinal anesthesia

Answer 42

subarachnoid space

Question 43

what is the limitation with spinal anesthesia

Answer 43

duration is only 1-4 hours

Question 44

what is one main initial CNS symptom of local anesthetic system toxicity

Answer 44

tongue paralysis

Question 45

local anesthetic system toxicity can present with __ and __

Answer 45

tonic clonic seizures respiratory depression

Question 46

what are 2 ways in which local anesthetic system toxicity is treated

Answer 46

IV diazepams for seizures succinylcholine to suppress muscle reactions

Question 47

what local anesthetic is the most cardiotoxic

Answer 47

Bupivacaine