Local Anesthetics

Question 1

shortest half life?

Answer 1

procaine (1-2 mins)

Question 2

longest half life?

Answer 2

ropivocaine (4.2 hours)

Question 3

MOA of local anesthetic

Answer 3

state-dependent and use-dependent blockade of Na channels

Question 4

what state enhances local anesthetic activity?

Answer 4

hyperkalemia

Question 5

what state antagonizes local anesthetic activity?

Answer 5

hypercalcemia

Question 6

all local anesthetics are vasodilators EXCEPT for?

Answer 6

cocaine
vasoconstrictor
prevents reuptake of NE and dopa

Question 7

ester local anesthetic
for extravasation complications from venipuncture, inadvertent intra-arterial injections
SE: antibody formation
shortest half life among local anesthetics
metabolite = PABA

Answer 7

procaine
novocaine, choloroprocaine

mainly topical

Question 8

ester local anesthetic
for topical anesthesia; dental anesthesia
SE: skin irritation, antibody formation
used cautiously when treating sunburns or large areas of skin

Answer 8

benzocaine

butamben

Question 9

ester local anesthetic
drug of abuse
intrinsic sympathomimetic activity
vasoconstriction (bec of catecholamines)
SE: antibody formation, abuse liability, severe hypertension, cerebral hemorrhage, cariac arrhythmias, myocardial infarction, stroke

Answer 9

cocaine

Question 10

ester local anesthetic
for spinal anesthesia, epidural anesthesia, topical ophthalmic anesthesia
SE: antibody formation
10x more potent that procaine, 10x more toxic

Answer 10

tetracaine

Question 11

amide local anesthetic

anti-arrhythmic (group 1B activity; used post-MI and for digitalis toxicity)

Answer 11

lidocaine

Question 12

most common arrhythmia secondary to digitalis?

Answer 12

PVC

Question 13

amide local anesthetic
for dental anesthesia
SE: methemoglobinemia (administer methylene blue)

Answer 13

prilocaine

mepivacaine

Question 14

amide local anesthetic
for epidural anesthesia, intrathecal anesthesia
SE: severe CV toxicity, hypotension, arrhythmias
use with caution in pregnant women
CI IN IV REGIONAL ANESTHESIA
longer DOA than lidocaine but NOT given topically or IV

Answer 14

bupivacaine

levobupivacaine

Question 15

how do you treat cardiotoxicity secondary to bupivacaine and ropivacaine?

Answer 15

intralipid (fat emulsion used in TPN)

binds to bupivacaine/ropivacaine, which is lipophilic

Question 16

amide local anesthetic
for epidural anesthesia
SE: cardiotoxicity
longest half life among local anesthetics
CI IN IV REGIONAL ANESTHESIA

Answer 16

ropivacaine