Neuromuscular blockers are classified as (a) nondepolarizing neuromuscular blockers or (b) depolarizing neuromuscular blockers (succinylcholine).
Nondepolarizing neuromuscular blockers compete with acetylcholine for the active binding sites at the postsynaptic nicotinic acetylcholine receptor and are also called competitive antagonists.
Depolarizing neuromuscular blockers act as agonists (they are similar in structure to acetylcholine) at postsynaptic nicotinic acetylcholine receptors and cause prolonged membrane depolarization resulting in neuromuscular blockade.