NMBD Reversal Agents (Ex IV)

Question 1

How long, generally, until NMJ blockade is fully reversed with neostigmine?

Answer 1

20-30 min

Question 2

Do AChE inhibitors work with deep neuromuscular blockade?

Answer 2

No

Question 3

Reversal of NMJ blockade is dependent on these 5 factors:

Answer 3

1. Depth of block
2. AChE-i choice
3. Dose administered
4. Rate of plasma clearance of NMBD
5. Anesthetic agent and depth

Question 4

Which paralytic has to be reconstituted with 10mL of H₂O ?

Answer 4

Vecuronium

Question 5

What is the dosage of neostigmine and its max?

Answer 5

40 - 70 mcg/kg

max: 5mg

Question 6

What is the onset and duration of neostigmine?

Answer 6

Onset: 5 - 10 min
Duration: 60 min

Question 7

What is the dosage of edrophonium?

Answer 7

0.5 - 1 mg/kg

Question 8

What is the onset and duration of edrophonium?

Answer 8

Onset: 1-2 min
Duration: 5-15 min

Question 9

What percentage of neostigmine is renally excreted?

Answer 9

50%

Question 10

What percentage of both pyridostigmine and edrophonium are renally excreted?

Answer 10

75%

Question 11

How are NMB reversal agents cleared if the patient has no innate renal function?

Answer 11

30 - 50% cleared hepatically

Question 12

What is the major side effect of NMBD reversal agents?

Answer 12

↑PSNS activity (from increased nACh and mACh activity)
SLUDGE-M symptoms

Question 13

What drugs would be coupled with NMBD reversal agents to prevent adverse side effects from these drugs?

Answer 13

Anti-cholinergic / Anti-muscarinics

• Atropine
• Glycopyrrolate

Question 14

If you’re concerned about someone’s cardiac status due to existing disease, which Anticholinergic drug would you use?

Answer 14

Glycopyrrolate

Question 15

What NMB reversal drug is glycopyrrolate used with?

Answer 15

• Neostigmine

Question 16

What NMB reversal is atropine used with?

Answer 16

Edrophonium

Question 17

What is the dose of Atropine?

Answer 17

7 - 10 mcg/kg

Question 18

What common side effects are seen after atropine administration?

Answer 18

• Mydriasis (pupil dilation)
• initial Tachycardia

Question 19

How long does glycopyrrolate need to be administered over?

Answer 19

2 - 5 min

Question 20

What is the dose and max for glycopyrrolate?

Answer 20

7 - 15 mcg/kg

1mg maximum

Question 21

What reversal drug is specific to mivacurium?

Answer 21

Purified human plasma cholinesterase

Question 22

What reversal drug is specific to gantacurium?

Answer 22

Cystiene

Question 23

What reversal drug is very specific to rocuronium? What other NMBDs is this drug effective in reversing?

Answer 23

Sugammadex (Bridion)

Aminosteroids

Question 24

What type of drug is sugammadex?

Answer 24

Selective relaxant-binding agent

Question 25

What should be known about sugammadex’s organic structure and physical properties? (3)

Answer 25

• γ-cyclodextrin
• Dextrose units from starch
• Highly H₂O-soluble (large renal excretion)

Question 26

What is the MOA of Sugammadex?

Answer 26

Encapsulates aminosteroids (mostly rocuronium) via:

• Van der Waals forces
• H-bonds
• Hydrophobic interactions

Question 27

What drugs does sugammadex work with?

Answer 27

Aminosteroids
Roc > Vec > Pancuronium

Question 28

What is the E ½ time of sugammadex?

Answer 28

2 hours

Question 29

How is sugammadex eliminated? What is an important consideration regarding excretions?

Answer 29

Urine:

• 70% gone in 6 hours
• 90% gone in 24 hours

Renal impairment: Contraindicated with dialysis pts

Question 30

Differentiate a moderate block vs a deep block.

Answer 30

• Moderate: 2/4 twitches on TOF
• Deep: No twitches to TOF (minimal posttetanic response)

Question 31

What is the Sugammadex dose for a moderate block?

Answer 31

2 mg/kg

Question 32

What is the Sugammadex dose for a deep block?

Answer 32

4 mg/kg

Question 33

What is the sugammadex dose for an extreme block?

Answer 33

8 - 16 mg/kg

Question 34

What are the side effects of Sugammadex? (4)

Answer 34

• marked Bradycardia
• dose-related N/V
• dose-related Pruritis
• dose-related Urticaria

Question 35

What drugs/conditions are relative contraindications to sugammadex?

Answer 35

• Contraceptives
• Toremifene (displaces NMB from sugammadex)
• Coagulopathy/bleeding
• ESRD (excreted renally)

Question 36

What is recurarization?

Answer 36

Resumption of NMJ blockade after period of reversal

Question 37

What s/s would indicate recurarization? (5)

Say you just brought the patient to PACU.

Answer 37

• ↓ SpO₂
• ↓ respiratory effort
• Floppy/uncoordinated
• Unresponsive
• suffocating feeling

Question 38

What drug and dose would be a good choice for a recurarizing patient in the PACU?
Why might this be a good choice?

Answer 38

• Neostigmine 0.05 mg/kg IV (40-70mcg/kg)
• Longer duration of action (60min)

Question 39

What is the only used long-acting NMBD? intermediate-acting NMBDs? short-acting NMBD?

Answer 39

Long
Pancuronium (AS)

Intermediate
Rocuronium (AS)
Vecuronium (AS)
Atracurium (BNZ)
Cisatracurium (BNZ)

Short
Mivacurium (BNZ)