ACh acts on N2 receptors (ligand-gated Na+/K+ receptors)
Block Na+ channels that propagate nerve impulse - local anaesthetics (lidocaine), tetrodotoxin
Inhibit ACh release - tetanus toxin, botulinum toxin
Competitive antagonists - vecuronium
N2 agonists - suxamethonium
Flaccid paralysis
Only cleared by plasma cholinesterase
Reversible anticholinesterases - edrophonium, neostigmine, physostigmine
Block activity of AChE
Diagnose and treat myasthenia gravis and treat glaucoma respectively
Irreversible anticholinesterases - organophosphates (pesticides, nerve gases)
Long-lived flaccid paralysis
Treat with pralidoxime within 10 minutes - cleaves OP-AChE complex