Vecuronium

doc. Vecuronium general anesthetic/intramuscular blocking agent

1. By: Ala’a F. Hassan/Al-mahmoudia G. Hospital
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It’s an aminosteroid non-
depolarizing neuromuscular
blocking agent [N-demethylated
derivative of pancuronium; with
approximate potency relative to
tubocurarine =6].

MECHANISM OF ACTION

Non depolarizing agents produce skeletal muscle paralysis by blockade at the
myoneural junction, competing with acetylcholine for cholinergic receptor sites
and binding with the nicotinic cholinergic receptor at the postjuctional
membrane, it has little agonist activity, with no depolarizing effect at the motor
endplate.
Muscle relaxation begins in the eyelids & jaw, progresses to the limbs, the
abdomen & finally the diaphragm & intercostals. It has absolutely no effect on
consciousness.

INDICATIONS

Facilitation of endotracheal intubation & laryngoscopy
Maintenance of paralysis following RSI (rapid sequence intubation)

DOSE

Intravenous: 0.1-0.2 mg/kg, repeat PRN
Supplemental dose after intubation: 0.02mg/kg
Dose for relaxation: with N2O 0.03mg/kg, with volatile anesthetics 0.03mg/kg.

2. PHARMACOKINETICS

• Available as lyophilized powder (has low stability in sol, so can’t be prepared
as ready to use sol with sufficient shelf life).
• Onset of action: IV 1 minute (good intubation conditions within 2.5-3.0
minutes).
• Duration of action: IV 30-60 minutes (intermediate action).
• Liver metabolism 30-40% (metabolites excreted in urine & bile)
• Elimination 40-50 % renal + 50-60 up to 90% hepatic, elimination t1/2 51-117
min [3-OH metabolite (3-deacetylvecuronium accumulate with renal failure
and may be responsible for delayed recovery)].
• Plasma clearance range 3-5ml/min with renal intact pt.
• Its compatible with 0.9% N/S , 5% G/W & lactated ringer sol.

SIDE EFFECTS

Associated side effects are rare, cardiovascular events are minimal while
occasional sever bronchospasm reported due histamine release.
Dysrhythemia, hyper- or hypotension reported as well as skeletal muscle
weakness & paralysis.

CONTRAINDICATIONS –PRECAUTIONS & MONITORING

 Hypersensitivity.
 Pregnancy, risk category (C).
 History of malignant hyperthermia (monitor temperature).
 Cardiac diseases (monitor heart rhythm, blood pressure & pulse oximetry).
 Respiratory disease (it causes respiratory paralysis & prolonged apnea).
 Narrow-angle glaucoma.
 Elderly, liver disease (prolong duration of action due to decreased clearance)
or debilitated patients.
 Must be ready to intubate as soon as given, use cricoid pressure to secure
airway from gastric regurgitation.
 Dehydration monitor fluid intake & output), electrolyte or acid/base
imbalance (potentiates the actions).
 Neuromuscular disease (prolonged effects, i.e. myasthenia gravis).

3. INTERACTIONS

• Volatile anesthetics ---potentiate effect in dose dependent fashion.
(Isoflurane, sevoflurane, desflurane, halothane & least effect with nitrous
oxide)
• Opiates & fentanyl --- bradycardia & asystole reported.
• Cholinergic agonists ---antagonizes effect.
(Neostigmine, pyridostigmine, edrophonium etc…)
• Succinylcholine ---previous administration potentiate effect.
• Mg sulfate & Lithium --- potentiate effect.
• Antiepileptics (carbamazepine & phenytoin) ---decreases efficacy.
• Antibiotics (AG, clindamycin, piperacillin, polymyxin anti-inf.) ---enhances
effect.
• Antiarrhythmics ---potentiates effect.