Neonatal Intensive Care UnitChildren's Hospital


Disclaimer to the On-line Edition
This Manual has been designed for use in the NICU at London Health Sciences Centre (LHSC), London, Ontario, Canada, and represents clinical practice at this institution. The information contained within the Manual may not be applicable to other centres. If users of this Manual are not familiar with a drug, it is recommended that the official monograph be consulted before it is prescribed and administered. Any user of this information is advised that the contributors, Editor and LHSC are not responsible for any errors or omissions, and / or any consequences arising from the use of the information in this Manual.



  • used to produce skeletal muscle relaxation/paralysis in uncooperative neonates who are mechanically ventilated


  • vecuronium competes with acetylcholine for receptor sites on the postjunctional membrane, thereby interrupting transmission of nerve impulses at the neuromuscular junction
  • it is a non-depolarizing agent; this means that muscular paralysis can be reversed if the concentration of acetylcholine is increased, by using an anticholinesterase inhibitor such as neostigmine, edrophonium or pyridostigmine
  • prematurity, acidosis, hypothermia and use within the first week are factors that dictate a low dose
  • the dose and duration do not, in general, predict the time to recovery; 20 hours in an average time to full recovery - this, however, can be prolonged by prematurity and renal failure
  • vecuronium and its metabolites appear to be excreted principally in feces via biliary elimination
  • approximately 20-30% of vecuronium is excreted in the urine, principally as unchanged drug
  • note that the elimination of pancuronium is quite different; pancuronium is eliminated mainly unchanged by the kidneys, a small amount is excreted in the bile

Side Effects

  • local irritation (redness, induration) is relatively infrequent
  • cardiovascular effects (tachycardia, increased blood pressure) are minimal and uncommon; note that tachycardia and increased blood pressure are frequently seen with Pancuronium (this occurs via vagal blockade)
  • unlike some other neuromuscular blocking agents (eg. atracurium) vecuronium does not cause histamine release

Nursing Implications

  • once the infant is paralyzed, dramatic changes in the respiratory settings may be necessary
  • aminoglycoside antibiotics (eg. gentamicin) potentiate neuromuscular blockage, leading to increased skeletal muscle relaxation
  • opiates can cause CNS respiratory depression which can add to the respiratory depressant effects of vecuronium
  • monitor baseline electrolyte values since electrolyte imbalance can potentiate neuromuscular effects
  • respiration and heart rate should be monitored continuously
  • must have constant nursing observation
  • give eye care every 30-60 minutes; use methylcellulose 0.5% solution to keep eyes lubricated, apply eye pad covers
  • measure accurate intake and output; renal dysfunction may prolong duration of action
  • do not store in plastic containers or syringes, although plastic syringes may be used for administration; use only fresh solutions
  • blood gases must be done 20-30 minutes after first dose
  • observe the infant for return of skeletal muscle activity and consult the physician regarding further drug administration

Reversal of Neuromuscular Blockade

  • neuromuscular blockade can be reversed by administering a cholinesterase inhibitor such as neostigmine


    • give atropine prior to neostigmine, to prevent vagal reaction (bradycardia, bronchospasm, increased salivation)
    • neostigmine 0.06 mg/kg slow IV push by physician only
    • also give atropine 0.02 mg/kg IV push by physician only


  • dosage must be individualized in each case

Initial Dosage

  • 0.08 to 0.1 mg/kg, IV push, by a physician only
  • in the presence of potent inhalational anesthetics, the neuromuscular blocking effect of vecuronium is enhanced, and the initial vecuronium dose may be reduced
  • prior administration of succinylcholine may enhance the neuromuscular blocking affect and duration of action of vecuronium

Maintenance Dosage

  • maintenance doses of 0.01 to 0.015 mg/kg have been given to patients who are receiving inhalational anaesthesia during surgical procedures; since the neuromuscular blocking action of vecuronium is slightly enhanced in the presence of inhalational anaesthetics, infants who are not receiving inhalational anaesthesia may require a higher maintenance dose than listed above
  • given IV push by a physician only
  • Children 7 weeks to 1 year are moderately more sensitive to vecuronium on a mg/kg basis than adults and take about 1 1/2 times as long to recover. The recovery time (spontaneous recovery of the twitch response from 25% to 75% of the control response) following administration of vecuronium 0.08-0.1mg/kg to adults under balanced or halothane anaesthesia is about 15-25 minutes. Repeated administration of maintenance doses of vecuronium appears to have little, if any, cumulative effect on the rate of recovery from neuromuscular blockade.

Continuous IV Infusion

  1. an initial dose of 0.08 to 0.1 mg/kg, IV push, by a physician only.
  2. a continuous IV infusion may be started only after spontaneous recovery from the initial IV dose is evident.
  3. an initial vecuronium infusion rate of 1 mcg/kg/min is recommended following STEPS 1 and 2 above.

    in patients with renal or hepatic impairment or in premature neonates the dosage may need to be altered


  • 10 mg vial
  • reconstitute vial with 5mL of sterile water for injection to obtain a solution of 2mg/mL

Example of a Calculation

  • Baby's weight = 1.73 kg


    Dose = 0.08 mg/kg
    Dose = (0.08 mg/kg) (1.73 kg) = 0.1384 mg

    Concentration, after reconstitution = 2 mg/mL
    therefore, 0.1384 mg in 0.069 mL (Round off to 0.07mL)



    Proceed only after steps 1) and 2) under "Continuous IV infusion" have been completed.

    Initial vecuronium infusion rate = 1 mcg/kg/min

    Baby's weight = 1.73 kg
    Assume an infusion rate of 1 mL/h

    1 mcg/kg/min=1.73 mcg/min (for a 1.73 kg baby)
     =103.8 mcg/h

    Therefore, there will be 103.8 mcg in 1mL (ie. 1 hour's supply)

    Therefore, there will be 5190 mcg (5.19 mg) in 50mL


    1. Withdraw 7.6 mL from a 50 mL minibag. (There is an average of 5 mL OVERFILL in the minibags; also, 2.6 mL of drug will be injected into the minibag)
    2. Add 2.6 mL of reconstituted vecuronium (2 mg/mL) to the minibag (need 5.19 mg of drug)
    3. Mix minibag well. Run infusion at 1 mL/h.


  1. McEvoy G K (ed): AHFS Drug Information, American Society of Hospital Pharmacists, 1991.
  2. Drugs Dex, Denver, Colorado, 1992.
  3. Pagliaro LA and Pagliaro AM (ed): Problems in Pediatric Drug Therapy, 1987, Drug Intelligence Publ Inc, Hamilton, Illinois.
  4. Krogh CME et al (ed): Compendium of Pharmaceuticals and Specialties, Canadian Pharmaceutical Association, 1992.
  5. Milan EM and McFeely EJ: Memory Bank for Neonatal Drugs, 1990, Williams and Wilkins, Baltimore.
  6. Bhatt DR, Furman GI, Reber DJ et al: Neonatal Drug Formulary, 1990-1991, 2nd Edition, Fontana, California 92334.

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