Vecuronium Bromide
Norcuron®
Nondepolarizing Neuromuscular Blocking Agent

10/2/2005

Indications: as an adjunct to general anesthesia, to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation.

Action: Vecuronium is a nondepolarizing neuromuscular blocking agent. It is about a third more potent than pancuronium. Duration of neuromuscular blockade produced by vecuronium is shorter than that of pancuronium. The time to onset of paralysis decreases and the duration of maximum effect increases with increasing vecuronium doses.

The level of paralysis must be monitored. The use of a peripheral nerve stimulator is of benefit in assessing the degree of muscular relaxation.

Remember: Vecuronium has no known effect on consciousness, pain threshold or cerebration. Administration must be accompanied by adequate anesthesia or sedation.

Reversal: Neuromuscular block is reversed by acetylcholinesterase inhibitors such as neostigmine, edrophonium, and pyridostigmine. There have been no reports of recurarization following satisfactory reversal of vecuronium induced neuromuscular blockade. Fast recovery is a finding consistent with its short elimination half-life.

Dose: The amount requires to produce ninety percent suppression of a muscle twitch. Initial 0.08 to 0.10 mg/kg produces first depression of twitch in about one minute. Maximum neuromuscular block in about 3-5 minutes.

After stopping drug recovery of the control twitch is about 25 to 40 minutes. After injection of an INTUBATING dose. The distribution half-life following a single i.v. dose (range 0.025 to 0.280 mg/kg) is approximately 4 minutes. Elimination half-life over this same dosage range is approximately 65 to 75 minutes

If succinylcholine is used prior to vecuronium, the administration of vecuronium should be delayed until the patient starts recovering from succinylcholine-induced neuromuscular blockade.

Long Term Use: Rarely use of neuromuscular blocking drugs to facilitate mechanical ventilation in ICU settings may be associated with prolonged paralysis and/or skeletal muscle weakness. This is noticed during attempts to wean. Immobilized patients may develop disuse muscle atrophy. The benefits-to-risk ratio of neuromuscular blockade must be considered.

Reconstitution and stability: When reconstituted with bacteriostatic water for injection, use within 5 days. When reconstituted with recommended diluents, use within 24 hours. Single dose vial. Discard unused portion. Reconstitute each vial with 10 mL of bacteriostatic water for injection or 10 mL of compatible diluent to obtain a solution containing 1 mg/mL vecuronium bromide. Compatible diluents include: 0.9% sodium chloride injection, USP, 5% dextrose injection, USP, 5% dextrose and 0.9% sodium chloride injection, USP, sterile water for injection, USP and lactated Ringer's injection, USP.

Monitor: Whenever the use of vecuronium or any neuromuscular blocking agent is contemplated in the ICU, it is recommended that neuromuscular transmission be monitored continuously during administration and recovery with the help of a nerve stimulator. Additional doses of vecuronium or any other neuromuscular blocking agent should not be given before there is a definite response to T1 or to the first twitch. If no response is elicited, infusion administration should be discontinued until a response returns.

Train of Four is the test used to measure the degree of neuromuscular blockade. A peripheral nerve stimulator is used.

• Do a baseline measurement before paralytic agent is started to determine current necessary to obtain twitch.
• 20 mA may be enough for the patient.
• Complete and document until TOF to 2/4.
• Instructions
1. Attach 2 electrodes along the course of the ulnar nerve. (Temporal may be used.)
2. Connect the lead to the peripheral nerve stimulator by inserting the jacks into the Proximal (red) and Distal (black) output jacks. Connect the other end to the patient electrodes.
3. Turn the stimulator on. Select the current necessary (usually 20) for that patient to twitch when the stimuli is applied.
4. Press TOF once. It will deliver a train of four pulses where each is 0.5 seconds apart. Do NOT use the other buttons on the stimulator!

Count the number of twitches the patient had out of four (0/4, 1/4, 2/4, 3/4, 4/4.) Adjust the medication as ordered. Goal is 1/4 to 2/4 twitches.