#succinylcholine

Succinylcholine  Succinylcholine is an intravenous (IV) skeletal muscle relaxant used as an adjunct to general anaesthesia, to help with tracheal intubation, and to relax skeletal muscles during surgery or mechanical ventilation. It's referred to as "sux"

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Just thinking about the 2 groups

You should not give cholinesterase inhibitors to those getting succinylcholine (a depolarizing neuromuscular blocker) as they will just prolong the effects (because pseudocholinesterase AKA plasma cholinesterase is what actually breaks down succinylcholine and eliminates it).

With nondepolarizing neuromuscular blockers you can give cholinesterase inhibitors (should give in the event of overdose).  Nondepolarizing blockers quickly dissociate from the neuromuscular receptors (vs depolarizing which stays bound) and are then eliminated by hepatic metabolism and renal excretion. Cholinesterase inhibitors block the enzyme (cholinesterase) that breaks down acetylcholine at the synapse and thus cause you to have an increase in acetycholine with then competes with the nondepolarizing blockers at the neuromuscular receptors.  The receptors show preference for ACh and eventually the nondepolarizing blockers are all eliminated. The exception is atracurium.  It is nondepolarizing as well but is instead eliminated similarly to succinylcholine (with pseudocholinesterase rather then with hepatic breakdown and renal elimination). One should avoid giving cholinesterase inhibitors while using it as well because they will potentiate its effects and could lead to toxicity.