local anesthetics

Question 1

aromatic ring

Answer 1

lipid solubility and potency

more lipophilic = more potent

Question 2

amide linkage

Answer 2

stable to hydrolysis by plasma esterases, longer duration of action

Question 3

hydrophilic amine

Answer 3

duration of action

Question 4

pKa

Answer 4

onset of action

lower = faster

Question 5

dose

Answer 5

increase duration/success

Question 6

vasoconstructors

Answer 6

increase duration/success

decrease absorption

Question 7

a2 agonists

Answer 7

increase duration

Question 8

opioids

Answer 8

increase duration

decrease dose

Question 9

alkalinization

Answer 9

increase potency, increases pH

Question 10

pregnancy

Answer 10

increase potency

Question 11

renal failure

Answer 11

increase distribution

Question 12

hepatic failure

Answer 12

increase distribution

Question 13

cardiac failure

Answer 13

decrease hepatic bloodflow

Question 14

cholinesterase deficiency

Answer 14

decrease clearance

Question 15

nerve block factors

Answer 15

structure activity relationship
nerve fiber size
myelination
tissue pH
adjunctive agents

Question 16

use-dependent block

Answer 16

actively firing, repetitively stimulated is more sensitive

Question 17

phasic inhibition

Answer 17

high frequency stimulation blocked more readily

Question 18

tissue pH

Answer 18

inflamed/infected/acidic work less

Question 19

local anesthetic SE

Answer 19

low dose: CNS depression
high dose: CNS excitation/seizures
cytotoxicity (tx: diazepam)
arrhythmias
contractile failure
allergy
hypotension

Question 20

aminoesters (only one “i)

Answer 20

metabolism: pseudo-cholinesterase
allergy: PABA

Question 21

cocaine

Answer 21

sympathomimetic effects

use: topical to control bleeding after ENT procedures

Question 22

procaine

Answer 22

low potency
short duration

metabolized to PABA

Question 23

tetracaine

Answer 23

potent
long duration

use: spinal/epidural anesthesia

Question 24

dibucaine

Answer 24

topical for skin conditions

oral as antitussive

Question 25

aminoamides (2 “i”s)

Answer 25

liver metabolism
wide distribution
cross BBB and placental barrier

rare allergies

Question 26

lidocaine

Answer 26

intermediate duration

use: short-duration procedures

anti-arrhythmic agent

Question 27

prilocaine

Answer 27

intermediate duration

use: topical for infiltration anesthesia
toxicity: methemoglobinemia, cyanosis (tx: IV methylene blue)

Question 28

ropivacaine

Answer 28

potent
long duration

epidural nerve block

less motor block
less cardiotoxic

Question 29

bupivacaine

Answer 29

potent
long duration

obstetrics, epidural nerve block

SE: cardiac depression, ventricular arrhythmia

Question 30

levobupivacaine

Answer 30

less cardiotoxicity and CNS effects

use: epidural anesthesia