Local Anesthetic and Muscle Relaxant

Question 1

Spinal anesthesia

Answer 1

CSF in lumbar region→ blocks sympathetic fibers in subarachnoid space

Question 2

Epidural anesthesia

Answer 2

injection into epidural space

Question 3

Nerve block

Answer 3

Injection into peripheral nerve endings/ trunks

Question 4

Infiltration anesthesia

Answer 4

Injection into tissue

Question 5

Disadvantage of infiltration anesthesia

Answer 5

Requires large amount of drugs

Question 6

Anesthesia w/o disrupting normal body function

Answer 6

Infiltration anesthesia

Question 7

Bier’s block

Answer 7

IV regional anesthesia

Question 8

Esters differ from amides b/c

Answer 8

Esters: shorter duration of action and increase systemic toxicity

Question 9

Local anesthetic: weak acid or weak base

Answer 9

Weak base

Question 10

LA: Predominantly ionized or non-ionized

Answer 10

Ionized

Question 11

Hydrophobic pathway: In order for LA to cross the membrane, it must be ____ and once inside it becomes _____ (binds to Na+ ch)

Answer 11

Non-ionized, ionized

Question 12

The closer the pka is to physio pH, the higher the concentration of the drug in the _____

Answer 12

non-ionized form (faster membrane transport –> faster onset of action)

Question 13

Drug always in the non-ionized form; very lipphilic

Answer 13

Benzocaine

Question 14

Topical use only

Answer 14

Benzocaine

Question 15

Makes pH more basic and increase non-ionized drug concentration

Answer 15

Bicarbonate

Question 16

LA: more effective in resting axon or rapidly firing axon

Answer 16

Rapidly firing axon

Question 17

Potency of the LA drugs are correlated to

Answer 17

Lipid solubility and duration of action

Question 18

LA duration of action is dependent on

Answer 18

site of action

Question 19

LA toxic effects are dependent on

Answer 19

half life

Question 20

Absorption is affected by:

Answer 20

dosage, site of injection, drug-tissue binding, chemical properties of the drug, local blood flow, vasoconstricting agents (epinephrine)

Question 21

Vasoconstricting agent would do what to LA

Answer 21

Decrease diffusion of drug –> prolong duration of action
Decrease systemic absorption
Decreases risk of systemic toxicity

Question 22

Amides metabolized by

Answer 22

CYP450s in the liver

Question 23

Esters metabolized by

Answer 23

Butyrycholinesterases in the plasma

Question 24

Metabolites of esters and amides excreted via

Answer 24

renal

Question 25

Pt w/ hepatic dz (reducing their hepatic blood flow) requires LA, do you give them an ester or amide?

Answer 25

Ester

Question 26

Block not limited to intended site

Answer 26

Differential block

Question 27

More sensitive: small diameter or large?

Answer 27

Small

Question 28

More sensitive: myelinated or unmyelinated

Answer 28

Unmyelinated

Question 29

More sensitve: fast or slow conduction velocity

Answer 29

slow conduction

Question 30

Allergic rxn more common for: amides or esters?

Answer 30

Esters

Question 31

How to decrease cardiovascular toxicity when using bupivacaine

Answer 31

IV lipid administration "lipid sink"

Question 32

Produces methemoglobinemia

Answer 32

Prilocaine, benzocaine

Question 33

Transient neurological symptoms (transient pain and dysethesia) seen in

Answer 33

lidocaine use for spinal anesthesia

Question 34

Esters LA (4)

Answer 34

Procaine, tetracaine, benzocaine, cocaine

Question 35

Procaine use

Answer 35

infiltration anesthesia and diagnostic nerve block

Question 36

LA Shortest duration of action

Answer 36

Procaine

Question 37

16x more potent and more toxin than procaine

Answer 37

Tetracaine

Question 38

Tetracaine uses

Answer 38

DOC: retrobulbar ophthalmic use Spinal anesthesia→ with 10% dextrose to increase specific gravity→ more dense than CSF→ hyperbaric

Question 39

Lidocaine uses

Answer 39

infiltration blocks and epidural anesthesia

Question 40

Highest rate of clearance of the amides

Answer 40

Prilocaine

Question 41

Do not use prilocaine in pt w/

Answer 41

methemoglobinemia, cardiac or respiratory dz

Question 42

Amide w/ greatest cardiotoxicity

Answer 42

Bupivacaine

Question 43

Why bupivacaine causes greater cardiotoxicty than other amides

Answer 43

diffuse away from cardiac channels slower

Question 44

Drug use as epidural during labor and childbirth

Answer 44

Bupivacaine

Question 45

S-enantiomer, less lipid soluble (more rapid clearing) than bupivacaine

Answer 45

Ropivacaine

Question 46

vaso-constricting effects at clinical dose

Answer 46

Ropivacaine

Question 47

DOC pierpheral block

Answer 47

Mepivacaine

Question 48

Inverse differential block→ causes motor block before or without sensory block

Answer 48

Etidocaine

Question 49

Drug w/ both amide and ester group

Answer 49

articaine

Question 50

Largely use in dental medicine

Answer 50

Articaine and prilocaine

Question 51

Centrally-acting spasmolytic

Answer 51

Baclofen, cylcobenzaprine, diazepam, tizanidnie

Question 52

Direct-acting spasmolytic

Answer 52

Dantrolene, botulinum toxin

Question 53

Spasmolytic target proteins

Answer 53

GABA(a), GABA(b), alpha2, Ca2+ ch

Question 54

Muscle relaxant w/ both pre and post synaptic inhibition of spinal cord

Answer 54

Tizanidine

Question 55

Tizanidine SE

Answer 55

Sedation, hepatotoxicity

Question 56

Muscle relaxant w/ limited muscle weakness

Answer 56

Tizanidine

Question 57

Tx for neuroleptic malignant syndrome

Answer 57

Dantrolene

Question 58

Tx for malignant hyperhtermia

Answer 58

Dantrolene

Question 59

Drug that interferes w/ excitation-contraction coupling of actin and myosin

Answer 59

Dantrolene

Question 60

Drug that is injected locally to control muscle spasm following stroke or neurological injury

Answer 60

Botox

Question 61

Inhibits pain transmission in dorsal horn via alpha2 receptors

Answer 61

Tizanidine