Pharm Tb3 Local Anesthetics

Front 1

what is procain

Back 1

ester linked local anesthetic - short duration

Front 2

what is tetracain

Back 2

ester linked local anesthetic - moderate duration

Front 3

what is cocaine

Back 3

ester linked local anesthetic -

Front 4

what is benzocain

Back 4

ester linked local anesthetic - non-amine that is lacking positive charge

Front 5

what is the vascular effect of cocaine?

Back 5

potent vasoconstrictor due to inhbiito of NE uptake into sympathetic nuerons

Front 6

what can occur at the injection site with cocain?

Back 6

local tissue necrosis due to vasoconstriction

Front 7

what is the CNS effect of cocaine?

Back 7

potent CNS stimulant

Front 8

what does cocaine do in systemic circulation?

Back 8

hyperpyrexia, HTN, stroke and sudden cardiac death, mania and paranoia

Front 9

what is cocain used for?

Back 9

only as a topic anesthesia for surgery of the mucous membranes

Front 10

what is lidocain?

Back 10

amide linkage local anestetic with short duration

Front 11

what is mepivacian?

Back 11

amide linkage local anesthetic with moderate duration

Front 12

what is mepivacian used for?

Back 12

infiltrative local anesthesia, nerve block and spinal or epidural anesthesia

Front 13

what is bupivacain?

Back 13

long duration amide linked local anesthetic

Front 14

what is bupivacain used for?

Back 14

epidural and spinal anesthesia only

Front 15

what is the major adverse side effect of bupivcain?e

Back 15

significant cardiovascular toxicity

Front 16

what is the mechanism of local anesthetics?

Back 16

reversibly bind to the neural sodium channel when it is int open or closed state and decreases sodium current = inhibit inpulse conduction along the axon

Front 17

when do local anesthetics not bind the sodium channel?

Back 17

when the channel is in the resting state

Front 18

what is rest block or voltage dependent block?

Back 18

more sodium channels remain inactivated at all membrane potentials = decreased sodium current

Front 19

is resting block depending or independent of stimulation rate?

Back 19

independent

Front 20

what is rate dependent block?

Back 20

recovery of inactivated sodium channesl is prolonged

Front 21

when does rate dependent block predominate?

Back 21

at low drug concentrations

Front 22

when does rest dependent block predominate?

Back 22

at high drug concentration

Front 23

what is the most prevelant type of conduction block

Back 23

except at very onset and offset - rest block predominates

Front 24

what happens as local anesthetics become more lipid solulable and increase in molecular weight?

Back 24

they are more potent, slower to dissociate, more toxic and more accessible to the site of action

Front 25

what is the duration of local anesthetics dependent on?

Back 25

its retention at the stie of administration

Front 26

what is the termination of local anesthetics determined by?

Back 26

tissue blood flow - terminatio is due to systemic absorption

Front 27

what is local anesthetic toxicity dependent on?

Back 27

plasma concentration

Front 28

what is the most important aspect concerning systemic absorption?

Back 28

intrinsic blood flow

Front 29

what is the most common allergic reaction to local anesthetics associated with?

Back 29

PABA - procain and tertracain

Front 30

what are the symptoms of the systemic effects of local anesthetics?

Back 30

drowsiness, tongue numbness, muscle tremor, diplopia, nystagmus, unconsciousness, tonic-clonic seizures, hypotension, coma, respiratory arrest and cardiovascular collapse

Front 31

what is the effect of vasocontrictors when used with local anesthetics?

Back 31

they prolong the duration of action by reducing the rate of systemic absorption - also reducing systemic toxicity

Front 32

how are esters metabolied?

Back 32

metabolized to inactive agents by plasma esterases (pseudocholinesterases)

Front 33

how are amides metabolized/

Back 33

hepatically - dependent on normal hepatic blood flow and function - metabolites can cause grand mal seizures and depress respiration

Front 34

what is the sensitivity of nerve fibers to local anesthetics?

Back 34

small unmyelinated fibers with slow conduction (C and A delta) are more sensitive than large myelinated fibers with rapid conduction

Front 35

what is the most to least senstive nerve fibers?

Back 35

pain, touch, adrenergic vasoconstriction, temperature, proprioception, motor function

Front 36

how can lidocain but used topically?

Back 36

by iontophoresis - a direct electrical charge forcing the drug into cutaneous tissues

Front 37

what drug is used for infiltration anesthesia?

Back 37

lidocain - direct injection into tissue without regard to the course of cutaneous nerves

Front 38

what is nerve block?

Back 38

direct injection itno tissue directly adjacent to a peripheral nerve or nerve plexus

Front 39

what is spinal anethesia?

Back 39

injection into the CSF that blocks perception of pain, touch, temperature, proprioception nad motor functions of the areas controlled by spinal cord below injection site

Front 40

what is a major adverse effect of spinal anesthesia?

Back 40

significant hypotension if anesthesia extends to the ANS nerve root in the thoracic region

Front 41

what is epidural anesthesia?

Back 41

injecting into the epidural space targeting the spinal nerve root

Front 42

what drug is used for epidurals?

Back 42

mepivacain or bupivacain