How do depolarizing neuromuscular blockers function?

Depolarizing neuromuscular blockers function by agonizing nicotinic receptors. These agents mimic the action of acetylcholine, the neurotransmitter that normally binds to nicotinic receptors on the motor end plate of the neuromuscular junction. When a depolarizing neuromuscular blocker is administered, it binds to these receptors and causes a persistent depolarization of the muscle membrane. This sustained depolarization prevents the muscles from repolarizing and leads to temporary paralysis, as the muscle cannot respond to further stimulation from acetylcholine.

This mechanism is what distinguishes depolarizing blockers from non-depolarizing blockers, which instead act as competitive antagonists. By understanding this action, it becomes clear why agonizing nicotinic receptors is fundamental to the function of depolarizing neuromuscular blockers.