NMB reversal agents & anticholinergics

Question 1

What type of bond is formed when edrophonium binds to the anionic site on acetylcholinesterase?
a. electrostatic
b. hydrogen
c. covalent
d. ester

Answer 1

a. electrostatic

Question 2

Acetylcholinesterase terminates the effect of acetylcholine by

Answer 2

hydrolyzing it into choline & acetate

Question 3

We can reverse the effects of neuromuscular blockers by

Answer 3

giving a drug that inhibits AchE at the neuromuscular junction

Question 4

AchE inhibitors used to reverse the effects of nondepolarizing NMBs include

Answer 4

edrophonium
neostigmine
pyridostigmine

Question 5

AchE inhibitors reverse the effects of NMBs in two ways:

Answer 5

enzyme inhibition
presynaptic effects

Question 6

Pseudocholinesterase is inhibited by

Answer 6

neostigmine & pyridostigmine; therefore, if succinylcholine is given after either, the duration of succinylcholine will be prolonged

Question 7

AchE inhibiting drugs bind to and inhibit AchE by interacting with these sites in one of three ways:

Answer 7

electrostatic attachment
formation of carbamyl esters
phosphorylation

Question 8

In what ways does neostigmine bind to the esteratic site of acetylcholinesterase?

Answer 8

carbamyl ester complex

Question 9

In what way does edrophonium bind to the anionic site of acetylcholinesterase?

Answer 9

electrostatic bond

Question 10

In what ways does edrophonium bind to the esteratic site of acetylcholinesterase?

Answer 10

hydrogen bond

Question 11

In what ways does organophosphate bind to the esteratic site of acetylcholinesterase?

Answer 11

phosphorylated enzyme

Question 12

The primary mechanism of edrophonium is most likely

Answer 12

presynaptic

Question 13

Examples of competitive inhibition of NMB reversal agents include

Answer 13

edrophonium, neostigmine, pyridostigmine, physostigmine

Question 14

Examples of non-competitive inhibition of NMB reversal agents include

Answer 14

organophosphates
echothiopate

Question 15

Which statements regarding anticholinesterase drugs are true?
a. 50% of neostigmine is metabolized by the liver
b. edrophonium + neostigmine has a synergistic effect
c. renal failure necessitates a second dose
d. neostigmine is more potent than pyridostigmine

Answer 15

a. 50% of neostigmine is metabolized by the liver
d. neostigmine is more potent than pyridostigmine

Question 16

To reduce the risk of cholinergic side effects ______________ is always administered with an acetylcholinesterase inhibitor

Answer 16

anticholinergic drug

Question 17

_________ is bested paired with edrophonium

Answer 17

atropine

Question 18

__________ is best paired with neostigmine or pyridostigmine

Answer 18

glycopyrrolate

Question 19

The deeper the degree of neuromuscular blockade, the_____________ of the acetylcholinesterase inhibitor

Answer 19

longer the onset time

Question 20

AchE inhibitors have a ________ effect

Answer 20

ceiling effect above which additional drug does not produce a better recovery

Question 21

Mixing AchE inhibitors produces ___________ effect.

Answer 21

an additive

Question 22

A TOF ratio <0.9 increases the risk of

Answer 22

airway obstruction, hypoxemia events, and postoperative pulmonary complications

Question 23

Giving an excessive dose of an AchE inhibitor (beyond what is required for full recovery) can cause

Answer 23

paradoxical muscle weakness

Question 24

What is the dose of edrophonium?

Answer 24

0.5-1.0 mg/kg

Question 25

What is the onset of edrophonium?

Answer 25

1-2 min.

Question 26

What is the DOA of edrophonium?

Answer 26

30-60 min.

Question 27

What is the metabolism & elimination of edrophonium?

Answer 27

renal 75% liver 25%

Question 28

What is the dose of neostigmine?

Answer 28

0.02-0.07 mg/kg

Question 29

What is the onset of neostigmine?

Answer 29

5-15 min

Question 30

What is the DOA of neostigmine?

Answer 30

45-90 minutes

Question 31

What is the metabolism & elimination of neostigmine?

Answer 31

renal 50% liver 50%

Question 32

What is the dose of pyridostigmine?

Answer 32

0.1-0.3 mg/kg

Question 33

What is the onset of pyridostigmine?

Answer 33

10-20 min

Question 34

What is the duration of pyridostigmine?

Answer 34

60-120 min.

Question 35

What is the metabolism & elimination of pyridostigmine?

Answer 35

renal 75% liver 25%

Question 36

____________ prolongs the DOA for both AchE inhibitors and NMBs

Answer 36

renal failure - no need to adjust the dose of the AchE inhibitor

Question 37

Do any of the acetylcholinesterase inhibitors pass through the BBB?

Answer 37

only physostigmine- tertiary amine the rest (edrophonium, neostigmine, and pyridostigmine) do not b/c they are quaternary amines

Question 38

When compared to adults, antagonism with neostigmine is _______ in infants & children

Answer 38

neostigmine

Question 39

__________________ reduces the incidence of postoperative shivering.

Answer 39

Physostigmine (40 mcg/kg)

Question 40

_____________ produces analgesia

Answer 40

Intrathecal neostigmine (50-100 mcg)

Question 41

Side effects of intrathecal neostigmine include

Answer 41

nausea & vomiting, pruritus, and prolongation of sensory and motor block

Question 42

List 4 drugs that reduce the incidence of shivering in the PACU?

Answer 42

meperidine physostigmine clonidine dexmedetomidine

Question 43

Which side effect is LEAST likely to occur after neostigmine administration? a. bronchospasm b. mydriasis c. nausea d. prolonged QT interval

Answer 43

b. mydriasis (pupil dilation)

Question 44

AchE inhibitors cause _____________ side effects.

Answer 44

parasympathetic side effects

Question 45

Cholinergic side effects include

Answer 45

miosis lacrimation salivation bronchoconstriction bradycardia emesis diarrhea laxation urination

Question 46

The mnemonic for cholinergic side effects is

Answer 46

DUMBBELLS