NJM and local anesthetics

Question 1

What are the non-depolaring NMJ blockers?

Answer 1

Atracurium, mivacurium, pancuronium, rocuronium

Question 2

What is the depolaring NMJ blocker?

Answer 2

Succinylcholine

Question 3

What are the local anesthetic Amides?

Answer 3

bupivacaine, lidocaine, ropivacaine, articaine

Question 4

What are the local anesthetic Esters?

Answer 4

Benzocaine, cocaine hydrochloride

Question 5

Explain some of the properties of NMJ blockers.

Answer 5

1. cause complete relaxation of skeletal muscle
2. do not pass BBB, no CNS effects
3. First muscles blocked are small rapid moving, then limb/trunk, then intercostal, finally diaphragm.

Question 6

This drug is used in treatment of malignant hyperthermia and long-term control of muscle spasms.

Answer 6

Dantrolene

Question 7

Explain the properties of the non-depolarizing NMJ blockers

Answer 7

1. not metabolized by AchE
2. Competitive inhibition of Ach
3. Reversed by physostigmine/neostigmine

Question 8

The NMJ blockers that end in “curium” have what properties?

Answer 8

1. Histamine release

2. Few vagal/ganglionic blocking effects

Question 9

The NMJ blockers that end in “curonium” have what properties?

Answer 9

1. Block ganglionic resulting in tachycardia

Rocuronium has little histamine release or tachycardia

Question 10

This drug is metabolized by plasma cholinesterase causing the short duration.

Answer 10

Mivacurium

Question 11

This drug has rapid onset, intermediate duration and is used to rapidly relax laryngeal and jaw muscles for tracheal intubation.

Answer 11

Rocuronium

Question 12

This drug undergoes Hofmann reaction that is temperature and pH dependent.

Answer 12

Atracurium

Useful for patients with liver or renal failure

Question 13

This drug has a long duration and is the 2nd drug used in lethal injection protocol.

Answer 13

Pancuronium

Question 14

This drug is used for very short procedures such as intubation.

Answer 14

Succinylcholine

Question 15

This drug causes initial fasciculations in the chest and abdomen. The minor twitching occur immediately.

Answer 15

Succinylcholine

Question 16

This drug alters the electro-chemical driving force by causing what?

Answer 16

Succinylcholine.

Excessive opening of nicotinic Ach receptors

Question 17

What are the 2 phases of action of succinylcholine?

Answer 17

phase 1: fast onset, single dose, neostigmine augments blocking action.

Phase 2: slow onset,after prolonged infusion or 10X dose, neostigmine antagonizes.

Question 18

What are the 3 parts of all local anesthetics?

Answer 18

1. lipophilic domain allow entry into neuronal axon.
2. intermediate chain; amides - liver metabolized. Esters - blood metabolized.
3. hydrophilic N terminal for inhibitory Na action.

Question 19

An acidic environment will charge LA, can they enter neurons?

Answer 19

No, must be uncharged to enter neurons.

Charged once inside to cause Na block.

Question 20

What is the rule for channels and local anesthetics?

Answer 20

More active channels, greater inhibition by LA

Question 21

How does axon size affect blockade?

Answer 21

Small axons are first to be blocked. (C fibers)

Large axons blocked last. (motor neurons)

Question 22

What produces surface anesthesia?

Answer 22

topical

Question 23

What produces field block anesthesia?

Answer 23

subcutaneous

Question 24

What produces nerve block anesthesia?

Answer 24

Peripheral nerves or plexus

Question 25

What produces spinal block?

Answer 25

Cerebral spinal in subarachnoid space

Question 26

What produces an epidural block?

Answer 26

Space within vertebral canal

Question 27

What is limited and what is not limited to injection sites?

Answer 27

Limited - spinal

Not limited - epidural

Question 28

This drug can decrease the rate of absorption and prolong anesthesia via vasoconstriction?

Answer 28

epinephrine

Question 29

Where should vasocontrictors not be co-adminstered with LA?

Answer 29

in peripheral sites due to loss of blood supply

Question 30

What side effects in the CNS occur in low concentrations?

Answer 30

sleepiness, dizziness, restlessnesss

Lidocaine can produce euphoria

Question 31

What side effects in the CNS occur in high concentrations?

Answer 31

nystagmus, shivering, respiratory failure, tremor, restlessness

Question 32

This drug is more cardiotoxic and can cause arrhythmias and hypotension.

Answer 32

Bupivacaine

Question 33

A high dose of what drug can cause conversion of hemoglobin to methemoglobin?

Answer 33

benzocaine

Question 34

This is the most widely used LA?

Answer 34

lidocaine

Question 35

This is used for infiltration, nerve block, spinal, epidural. and useful for analgesia during labor.

Answer 35

Bupivacaine

Question 36

This is a long acting, pure enantiomer used for procedures where motor block is undesirable (Labor)?

Answer 36

Ropivacaine

Question 37

This drug is the choice of dentists, it is metabolized by plasma carboxyesterase.

Answer 37

Articaine

Question 38

This drug is used topically for surface anesthesia.

Answer 38

Benzocaine

Question 39

This drug is used topically and only with inherent vasoconstrictive properties.

Answer 39

Cocaine hydrochloride

Question 40

Co-administration with epinephrine is unnecessary with?

Answer 40

Cocaine hydrochloride

Question 41

This drug has a very rapid time to onset and very short duration.

Answer 41

Succinylcholine.