Nicotinic receptor antagonists (general) and succinylcholine

Question 1

Nicotinic receptor antagonists (2 groups)

Answer 1

Ganglionic blocking agents (no longer used).

Neuromuscular blocking agents

Question 2

Neuromuscular blocking agents are also known as…

Answer 2

Paralytics

Muscle relaxants

Question 3

Neuromuscular blocking agents (2 groups)

Answer 3

Nondepolarizing neuromuscular blocking agents.

Depolarizing neuromuscular blocking agents.

Question 4

Why are the muscle relaxants “extremely dangerous compounds”?

Answer 4

May produce complete respiratory failure

Question 5

Paralytics - adverse effects

Answer 5

Anesthesia awareness.

Complete respiratory failure.

Question 6

Depolarizing neuromuscular blocking agents (1 drug)

Answer 6

Succinylcholine

Question 7

Succinylcholine - MOA

Answer 7

Binds to nicotinic receptors in skeletal muscle and causes persistent depolarization of the motor end plate. Initially it causes transient fasciculations, and then sustained muscle paralysis.

Question 8

How can the effect of succinylcholine be reversed?

Answer 8

It cannot be reversed, no antidote for overdose exists. However it is broken down by cholinesterase, and has a short duration of action (5-10 min).

Question 9

Succinylcholine - indications

Answer 9

Before and during surgery (muscle relaxant).

Facilitate intubation.

Question 10

Preferred neuromuscular blocker for adults with emergency airway situations

Answer 10

Succinylcholine

Question 11

Succinylcholine - cautions and contraindications

Answer 11

Pts with atypical cholinesterase.
Unhealed skeletal muscle injury and third-degree burns (hyperkalemia).
Conditions involving muscle weakness (hyperkalemia due to up-regulation of ACh receptors).
Children (more susceptible to consequence of hyperkalemia)

Question 12

Succinylcholine - adverse effects

Answer 12

Hyperkalemia and cardiac arrest.
Postoperative myalgia (neck, back, abdomen).
Malignant hyperthermia.