Which competitive nondepolarizing neuromuscular blocker is used to provide muscle relaxation and is reversed by neostigmine?

Which competitive nondepolarizing neuromuscular blocker is used to provide muscle relaxation and is reversed by neostigmine?

• A. Atracurium
• B. Pancuronium
• C. Vecuronium
• D. Succinylcholine

Answer: (B)

Nondepolarizing competitive neuromuscular blockers produce muscle relaxation by occupying nicotinic receptors at the neuromuscular junction, preventing acetylcholine from triggering contraction. Because they compete reversibly, increasing acetylcholine at the synapse with an acetylcholinesterase inhibitor like neostigmine outcompetes the blocker and restores muscle function. Pancuronium is a classic long-acting example of this type, so its effects are reversed by neostigmine through the same mechanism. In contrast, succinylcholine is a depolarizing blocker and is not reversed by neostigmine, which helps distinguish it from the nondepolarizing class.

Nondepolarizing competitive neuromuscular blockers produce muscle relaxation by occupying nicotinic receptors at the neuromuscular junction, preventing acetylcholine from triggering contraction. Because they compete reversibly, increasing acetylcholine at the synapse with an acetylcholinesterase inhibitor like neostigmine outcompetes the blocker and restores muscle function. Pancuronium is a classic long-acting example of this type, so its effects are reversed by neostigmine through the same mechanism. In contrast, succinylcholine is a depolarizing blocker and is not reversed by neostigmine, which helps distinguish it from the nondepolarizing class.