Vecuronium

• Intermediate-acting nondepolarizing neuromuscular blocker used for rapid sequence intubation (RSI) and for maintenance of neuromuscular blockade in the OR and ICU
• Compared with rocuronium, vecuronium has a slightly slower onset at typical doses and lacks an approved reversal with sugammadex in some regions (though sugammadex does effectively reverse it where available). Duration is intermediate but can be significantly prolonged in hepatic and renal dysfunction
• Typical RSI dose (adult): 0.1–0.2 mg/kg IV (often 0.15 mg/kg) based on ideal or adjusted body weight. Onset ~2–3 minutes, so it is less favored than rocuronium for true crash RSI but may be used where rocuronium/succinylcholine are contraindicated or unavailable
• ICU continuous paralysis: 0.8–1.7 mcg/kg/min IV (≈0.05–0.1 mg/kg/h) after a 0.1 mg/kg bolus, titrated to train-of-four (TOF) and clinical goals; use the lowest effective dose and minimize duration
• Like all NMBs, vecuronium has no sedative, amnestic, or analgesic properties—adequate analgesia and sedation are mandatory before and during paralysis
• Elimination is largely hepatic with biliary excretion and an active metabolite (3-desacetyl vecuronium) that is renally cleared; accumulation and prolonged paralysis are common in hepatic/renal dysfunction and with prolonged infusions

• Generic Name: Vecuronium bromide
• Brand Names: Norcuron, generics

Nondepolarizing neuromuscular blocker (NDNMB), aminosteroid; intermediate-acting. Competitively antagonizes acetylcholine at nicotinic receptors at the neuromuscular junction, producing flaccid skeletal muscle paralysis without fasciculations or initial muscle contractions (unlike succinylcholine).

Mechanism of Action:

• Competitive antagonist at nicotinic acetylcholine receptors at the neuromuscular junction
• Prevents acetylcholine from binding and depolarizing the motor endplate, resulting in flaccid skeletal muscle paralysis
• Nondepolarizing: Does not cause fasciculations or initial muscle contractions (unlike succinylcholine)
• Neuromuscular block can be reversed with acetylcholinesterase inhibitors (e.g., neostigmine with glycopyrrolate) or, where available, with sugammadex

Pharmacokinetics:

• Onset: ~2–3 minutes after 0.1 mg/kg; faster (~1.5–2 minutes) with 0.15–0.2 mg/kg RSI dosing
• Duration: Clinically significant paralysis ~25–40 minutes after 0.1 mg/kg in healthy adults; prolonged with higher doses, infusions, and in organ dysfunction
• Distribution: Volume of distribution ~0.2–0.4 L/kg; does not cross the blood–brain barrier
• Metabolism: Primarily hepatic deacetylation to 3-desacetyl vecuronium (active metabolite with ~80% potency of parent drug)
• Elimination: Biliary and renal excretion of parent drug and metabolites; elimination half-life ~50–80 minutes in healthy adults but significantly prolonged in hepatic and renal impairment
• Potentiation factors: Critical illness, hypothermia, acid–base and electrolyte disturbances, and interacting drugs (aminoglycosides, magnesium, some antiarrhythmics) can potentiate and prolong neuromuscular block

• Rapid sequence intubation (RSI) when a nondepolarizing agent is preferred due to contraindications to succinylcholine (e.g., hyperkalemia, neuromuscular disease, prolonged immobilization, major burns, crush injuries) and rocuronium is unavailable or less preferred
• Facilitation of mechanical ventilation and control of severe ventilator dyssynchrony in the ICU (e.g., severe ARDS), after optimization of sedation/analgesia and ventilator strategy
• Adjunct in the operating room to facilitate intubation and provide muscle relaxation during surgery (anesthesia-managed)

Available Forms:

• IV lyophilized powder: Usually supplied as 10 mg or 20 mg vials for reconstitution with sterile water or normal saline
• Common reconstitution: 10 mg in 10 mL (1 mg/mL) or 20 mg in 20 mL (1 mg/mL) for IV bolus dosing
• For continuous infusion: Vecuronium may be diluted in normal saline or D5W to institution-specific concentrations (e.g., 1–2 mg/mL) and titrated via infusion pump

Dosing – Vecuronium (Adult IV):

Always follow local protocol. Use ideal or adjusted body weight for dosing calculations, especially in obesity.

Contraindications:

• Known hypersensitivity to vecuronium, other aminosteroid NDNMBs (e.g., rocuronium, pancuronium), or formulation components
• Situations where airway cannot be secured or bag-mask ventilation is not assured (relative contraindication to any paralytic)

Major Precautions:

• Neuromuscular disorders (myasthenia gravis, Lambert–Eaton, motor neuron disease): Extreme sensitivity to nondepolarizing NMBs; use markedly reduced doses and expect prolonged block
• Hepatic and renal dysfunction: Decreased clearance of vecuronium and its active metabolite → prolonged paralysis; avoid prolonged infusions when possible
• Electrolyte abnormalities: Hypokalemia, hypocalcemia, hypermagnesemia and certain medications (aminoglycosides, magnesium, some antiarrhythmics, inhaled anesthetics) potentiate neuromuscular blockade
• Anaphylaxis: Rare but can be severe; be prepared with full resuscitation capacity whenever NMBs are administered
• Never administer without adequate analgesia and sedation: Locked-in, awake paralysis is a major patient safety and ethical issue

Common:

• Generally hemodynamically stable; minimal histamine release
• Mild tachycardia or hypotension in some patients
• Injection-site discomfort

Serious:

• Anaphylaxis, including bronchospasm, hypotension, and cardiovascular collapse
• Prolonged neuromuscular blockade, especially with infusions or organ dysfunction; can last hours to days in severe cases
• Residual paralysis and weakness leading to hypoventilation or inability to protect the airway if reversal and monitoring are inadequate
• Contribution to ICU-acquired weakness and myopathy when used for extended periods in critically ill patients
• Awareness under paralysis if inadequate sedation/analgesia provided during neuromuscular blockade

• Obesity: Dose based on ideal or adjusted body weight; avoid using full actual body weight to prevent overdosing and prolonged paralysis
• Hepatic dysfunction: Use lower end of dose range; avoid prolonged infusions due to decreased clearance and accumulation of parent drug and active metabolite
• Renal dysfunction: Active metabolite (3-desacetyl vecuronium) is renally cleared; accumulation can cause significantly prolonged paralysis, especially with repeated doses or infusions
• Elderly patients: May have reduced hepatic and renal function; use conservative dosing and monitor closely for prolonged effects
• Neuromuscular disease: Markedly reduced dose requirements (as low as 50% of standard dose) and prolonged duration; consult anesthesia/neurology when possible
• Pregnancy: Category C; use only when clearly needed; crosses placenta minimally but can affect fetal heart rate variability monitoring
• Pediatrics: Dosing similar to adults on mg/kg basis; infants <1 year may be more sensitive and have longer duration of action; neonates have immature neuromuscular junctions

• Continuous monitoring: ECG, blood pressure, and pulse oximetry during and after administration
• Ventilator parameters and capnography: Ensure adequate ventilation and oxygenation while paralyzed; maintain ETCO₂ in appropriate range
• Sedation/analgesia depth: Use clinical signs, hemodynamics, and, where available, processed EEG (e.g., BIS) since patient cannot report awareness; target BIS 40–60 or per protocol
• Neuromuscular monitoring (train-of-four): Essential when using repeated doses or infusions; target 1–2 twitches during therapeutic paralysis and full recovery (TOF ratio ≥0.9) before extubation or reversal
• Frequent reassessment: Continuously evaluate the necessity of continued neuromuscular blockade, particularly in ICU patients to minimize duration of paralysis
• Airway security: Ensure endotracheal tube position, cuff integrity, and ventilator circuit function before and throughout paralysis

• Lexicomp. (2025). Vecuronium: Drug information. Wolters Kluwer.
• Naguib, M., & Brull, S. J. (2018). Neuromuscular blocking agents and reversal agents. In Miller's Anesthesia (9th ed.). Elsevier.
• Papazian, L., Forel, J.-M., Gacouin, A., et al. (2010). Neuromuscular blockers in early acute respiratory distress syndrome. New England Journal of Medicine, 363(12), 1107–1116. https://doi.org/10.1056/NEJMoa1005372
• Marsch, S. C., Steiner, L., Bucher, E., et al. (2011). Succinylcholine versus rocuronium for rapid sequence intubation in intensive care: A prospective, randomized trial. Critical Care, 15(4), R199. https://doi.org/10.1186/cc10367
• Farkas, J. (2024). Rapid sequence intubation (RSI) and delayed sequence intubation (DSI) (IBCC). EMCrit Project. https://emcrit.org/ibcc/rsi/