depolarising neuromuscular blocker

Question 1

Name the depolarising neuromuscular blocker

Answer 1

Suxamethonium (succinylcholine)

Question 2

What does suxamethonium do?

Answer 2

causes short-lasting paralysis of the muscle

Question 3

What is the mechanism of action of suxamethonium?

Answer 3

Acts on and binds to nicotinic receptors to cause depolarisation of muscle membrane and thus inactivates the Na+ channels that propagate the action potential through the muscle. Prevents muscle contraction.

Question 4

What are some adverse effects of suxamethonium?

Answer 4

Hypotension, hyperkalaemia, bradycardia, muscle pain (resulting from spasm from initial depolarisation), raised intraocular pressure, fasciculations

Question 5

Can suxamethonium be hydrolysed by plasma cholinesterases?

Answer 5

yes - within a few minutes

Question 6

Why can suxamethonium cause paralysis?

Answer 6

Has a longer effect than acetylcholine i.e. does not allow muscle cell to depolarise