Mivacurium

• •Short procedures needing brief non-depolarizing relaxation

Onset 2–3 min. Duration 15–20 min (shortest NDMR). Plasma-cholinesterase metabolism → PROLONGED in pseudocholinesterase deficiency (like sux).

Histamine release with rapid/large doses → hypotension, flushing.

• !Histamine release (dose/rate-dependent)
• !PROLONGED block in pseudocholinesterase deficiency
• !Prolonged by anticholinesterases (neostigmine paradoxically prolongs it)

• ×Pseudocholinesterase deficiency (relative)
• ×Reactive airway (histamine)

• ★Only non-depolarizer metabolized by plasma cholinesterase → shortest-acting, but PROLONGED in atypical/deficient pseudocholinesterase (same populations as succinylcholine).
• ★Neostigmine can PROLONG it (inhibits the plasma cholinesterase that clears it) — reversal is nuanced.

• Succinylcholine

  Acetylcholine receptor agonist at the NMJ; sustained depolarization → fasciculations → flaccid paralysis. Hydrolyzed by plasma cholinesterase.

• Rocuronium

  Competitive antagonist at the NMJ nicotinic receptor.

• Sugammadex

  Encapsulates rocuronium > vecuronium > pancuronium in 1:1 complex. No effect on cisatracurium, atracurium, sux.

• Cisatracurium

  Competitive antagonist at the post-synaptic nicotinic ACh receptor at the neuromuscular junction. Single cis-cis isomer of atracurium (4× more potent, lower laudanosine production).

• Vecuronium

  Competitive nicotinic ACh-receptor antagonist at the NMJ. Aminosteroid → reversible by sugammadex.

• Atracurium

  Competitive nicotinic antagonist. Eliminated by HOFMANN elimination (spontaneous, temp/pH-dependent) + ester hydrolysis → organ-independent clearance.

• Pancuronium

  Competitive nicotinic antagonist. Also blocks cardiac muscarinic receptors (vagolytic) → tachycardia.

• •Stoelting & Hines, Pharmacology & Physiology in Anesthetic Practice, 6e
• •Miller's Anesthesia, 9e
• •FDA package insert