GasGasGas - Anaesthetic Science for Anaesthesia! Vecuronium for Anaesthetists + NMB monitoring
Mar 6, 2026
A deep dive into vecuronium: its class, formulation, dosing and pharmacokinetics. Discussion of mechanism at nicotinic receptors and common side effects and interactions. A clear primer on neuromuscular monitoring methods like TOF, DBS and PTC. Practical coverage of interpreting twitches, reversal thresholds and why objective monitoring matters for patient safety.
AI Snips
Chapters
Books
Transcript
Episode notes
Selective Nicotinic Blockade At The Neuromuscular Junction
- Vecuronium acts as a non-competitive antagonist at postjunctional nicotinic acetylcholine receptors with much greater potency at N2 (NMJ) than N1 (ganglionic) receptors.
- It is ~80× more potent at neuromuscular junction receptors than at vagal/ganglionic nicotinic receptors, reducing autonomic side effects compared with older agents.
Dosing Timing And Redosing Guidance
- Use 0.1 mg/kg vecuronium for intubation with an ED95 ≈50 μg/kg; expect onset 90–120 seconds, maximal blockade at 3–5 minutes and offset in 25–40 minutes.
- For maintenance give ~25% of intubating dose as top-ups or consider infusion; remember potency inversely affects onset (Bowman’s principle).
Cardiovascular Effects Metabolism And Clearance
- Vecuronium has minimal histamine release, may slightly increase cardiac output and lower SVR in large doses, and can reduce prothrombin time.
- Clearance involves hepatic metabolism including deacetylation to active metabolites excreted in bile, with 25–33% unchanged renal excretion and half-life ~30–80 minutes.
