Vecuronium Bromide is an FDA approved peripherally acting, monoquarternary, steroidal, non-depolarizing neuromuscular blocker with an intermediate duration of action used during general anesthesia to facilitate endotracheal intubation, to aid in surgical relaxation, and, less commonly, in the intensive care setting to achieve paralysis to facilitate mechanical ventilation for appropriately sedated patients. This neuromuscular blocking agent is often used to facilitate endotracheal intubation and surgical relaxation in patients under general anesthesia. It is structurally similar to pancuronium, differing only by the lack of a quaternizing methyl group in the 2-piperidino substitution; this results in a slight decrease in potency and an elimination of the vagolytic properties when compared to pancuronium. Vecuronium also has higher lipid solubility, which results in a higher amount of biliary elimination.[1]

The liver chiefly eliminates vecuronium due to its higher lipid solubility.  Poor liver function can cause prolonged effects. Vecuronium has three possible metabolites. The 3-hydroxy metabolite has 80% the neuromuscular blocking potency of vecuronium.  Therefore, prolonged use of vecuronium can result in the accumulation of this metabolite and significantly prolonged neuromuscular blocking effects. Renal excretion accounts for only about 30% of the elimination of vecuronium.  

Vecuronium has rarely seen off-label use to control refractory shivering in sedated patients during the administration of post-cardiac arrest therapeutic hypothermia. However, in this setting, the duration of action is prolonged, and it may mask seizure activity.[2][3]

Vecuronium is a nondepolarizing agent that achieves its skeletal muscle paralysis by competing with acetylcholine for cholinergic receptor sites and binding with the nicotinic cholinergic receptor at the postjunctional membrane. Anticholinesterases antagonize the neuromuscular blocking properties of vecuronium.[4] Also, the effects of vecuronium are reversible by sugammadex, a modified cyclodextrin which encapsulates the compound, rendering the drug ineffective.

When a patient is under balanced anesthesia, the time to recover to 25% of control is approximately 25 to 40 minutes, and recovery is usually 95% complete at about 45 to 65 minutes after the intubating dose. The presence of volatile halogenated anesthetics such as sevoflurane or desflurane slightly enhances the neuromuscular blocking action of vecuronium. If vecuronium is administered in conjunction with an inhalation induction of anesthesia with a volatile agent, the intubating dose of vecuronium is typically decreased by 15% due to the mild muscle relaxation effects of the volatile halogenated anesthetic.

Vecuronium is prepared as a lyophilized powder because it has poor stability in solution and therefore, would have a very short shelf life in this form; this requires the reconstitution of the drug before administration.  

The dose used for endotracheal intubation in the controlled setting prior to surgery:

• 0.08 mg/kg to 0.1 mg/kg intravenous (IV) over 60 seconds or 0.04 mg/kg to 0.06 mg/kg IV if succinylcholine was used, to allow its effects to subside before administering vecuronium.

The dose used for rapid sequence intubation:

• 0.1 mg/kg to 0.2 mg/kg IV, with the onset of intubation conditions occurring in less than 2 to 3 minutes

Maintenance for continued surgical relaxation:

• 0.01 mg/kg to 0.015 mg/kg IV to be given 20 to 45 minutes after the initial dose and every 12 to 15 minutes as needed

Maintenance for continuous Infusion (most commonly used for ICU paralysis to facilitate mechanical ventilation):

• Initial bolus dose of 0.08 mg/kg to 0.1 mg/kg IV starting 20 minutes post bolus recovery, followed by 0.05 mg/kg/hour to 0.07 mg/kg/hour IV.

The following adverse reactions have occurred in less than 1% of cases:

• Bronchospasm
• Hypotension
• Edema
• Sinus tachycardia
• Erythema
• Urticaria
• Flushing
• Pruritus
• Skin Rash

Hypersensitivity associated with histamine release leading to allergic reactions may occur, and in rare instances, life-threatening anaphylaxis may occur.  In general, when compared to other nondepolarizing neuromuscular-blocking agents such as pancuronium, rocuronium, or atracurium, the safety profile of vecuronium is favorable.[5]

Of all the neuromuscular blocking agents, vecuronium correlates with the least amount of histamine release; however, severe, there are still reports of life-threatening anaphylactic reactions occurring. Due to the excessive salivation that can occur with this histamine release, caution is necessary when administering vecuronium to patients with bronchospasm and asthma.[1]

Electrolyte abnormalities such as severe hypocalcemia, hypokalemia, or hypomagnesemia may potentiate the effects of vecuronium. Other relative contraindications to the use of vecuronium include myopathy, obesity, and neuromuscular diseases, such as Eaton-Lambert syndrome and myasthenia gravis, as these conditions may prolong the drug’s effect.

Vecuronium use requires caution in patients with underlying cardiac disease that may be associated with slower circulation time. Edema, poor circulation, and changes in fluid volume can delay the onset of muscle paralysis.

Due to its clearance via the liver, vecuronium use merits with caution in patients with liver failure or cirrhosis. Prolonged recovery from muscle paralysis may occur in patients with any kind of underlying liver disease. Caution is also necessary when administering vecuronium to renal failure patients, as hepatic elimination decreases in patients with uremia, and this may cause accumulation of the drug’s active 3-hydroxy metabolite.

Caution is advised when administering vecuronium to patients with burns greater than or equal to 20% of their total body surface area. Resistance to the muscle paralysis caused by vecuronium may occur several days after the injury and persist for several months after wound healing.