Topic overview

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Non-depolarizing blockers occupy Nm receptors without opening the ion channel, whereas succinylcholine activates the receptor and produces persistent depolarization followed by desensitization. Their effects differ in onset characteristics: non-depolarizers cause flaccid paralysis without initial fasciculations, while succinylcholine may cause brief fasciculations first. Paralysis typically progresses from smaller, faster muscles toward the diaphragm, with recovery in reverse order. Train-of-four patterns can help distinguish blockade types, and reversal depends on the agent: acetylcholinesterase inhibitors are used for non-depolarizers but are ineffective or may prolong succinylcholine’s phase I block. The lesson also highlights agent-specific pharmacokinetics, reversal options, and adverse effects.