Vecuronium Bromide
Also known as: Norcuron · Curlem · Rivecrum · Vecural · Org-NC-45 · Vecuronium bromide · Vecuronii bromidum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Muscle relaxation during anesthesia | 0.1 mg/kg | IV | initially (after meperidine and/or acepromazine pre-op 30 minutes before); may give subsequent incremental doses of 0.04 mg/kg | — | 🌎 NA |
| Muscle relaxation during anesthesia | 10-20 micrograms/kg | IV | — | — | 🌎 NA |
| Muscle relaxation (CRI maintenance with propofol-fentanyl) | 0.2 mg/kg/hr | IV | CRI | — | 🌎 NA |
| Muscle relaxation (CRI maintenance with fentanyl-isoflurane or fentanyl-sevoflurane) | 0.1 mg/kg/hr | IV | CRI | — | 🌎 NA |
| Neuromuscular blockade (loading dose) | 0.1 mg/kg | IV | initially | Produces blockade for 25-30 min | 🌍 EU |
| Neuromuscular blockade (maintenance) | 0.03 mg/kg increments OR 0.1-0.2 mg/kg/h | IV | PRN or CRI | As needed during surgery | 🌍 EU |
| Reversal of neuromuscular blockade | 8 mg/kg | IV | once | Immediate | 🌍 EU |
- Muscle relaxation during anesthesia: Duration of action after initial dose averages 25 minutes.
- Neuromuscular blockade (loading dose): Lower loading dose of 0.05 mg/kg IV produces shorter duration (16-19 min).
- Neuromuscular blockade (maintenance): Repeated doses are relatively non-cumulative in healthy animals.
- Reversal of neuromuscular blockade: Dose for Sugammadex to reverse vecuronium-induced blockade.
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Muscle relaxation during anesthesia | 20-40 micrograms/kg (0.02-0.04 mg/kg) | IV | — | — | 🌎 NA |
| Neuromuscular blockade (loading dose) | 0.1 mg/kg | IV | initially | Produces blockade for 25-30 min | 🌍 EU |
| Neuromuscular blockade (maintenance) | 0.03 mg/kg increments OR 0.1-0.2 mg/kg/h | IV | PRN or CRI | As needed during surgery | 🌍 EU |
- Neuromuscular blockade (loading dose): Lower loading dose of 0.05 mg/kg IV produces shorter duration (16-19 min).
- Neuromuscular blockade (maintenance): Repeated doses are relatively non-cumulative in healthy animals.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Vecuronium bromide is an intermediate-acting, synthetic, aminosteroid nondepolarizing neuromuscular blocking agent.
Key clinical features include:
- Surgical Adjunct: Used primarily as an adjunct to general anesthesia to produce profound skeletal muscle relaxation.
- Facilitates Procedures: Ideal for facilitating endotracheal intubation, mechanical ventilation, and delicate surgical procedures (e.g., ophthalmic or orthopedic surgeries).
- Cardiovascular Stability: Unlike some other neuromuscular blockers, it causes very minimal cardiovascular effects and generally does not trigger histamine release.
- Avian Use: Has been used topically to induce mydriasis (pupil dilation) in birds, as avian irises contain striated muscle.
CRITICAL CLINICAL PEARL: Vecuronium possesses NO analgesic, sedative, or amnestic properties. It paralyzes all skeletal muscles, including the diaphragm. Patients must be fully anesthetized, unconscious, and receiving positive pressure mechanical ventilation prior to and throughout its administration.
Mechanism of action
Vecuronium acts as a competitive antagonist at the nicotinic cholinergic receptors (nAChRs) located at the motor endplate of the neuromuscular junction.
- Mechanism: Vecuronium binds to the alpha subunits of the nAChR → prevents acetylcholine (ACh) from binding → inhibits depolarization of the muscle fiber → results in flaccid paralysis.
- Potency: It is highly potent, estimated to be equipotent to up to 3 times as potent as pancuronium on a weight basis, but with a shorter duration of action (approximately ⅓ to ½ as long).
Safety & warnings
Contraindications
- Known hypersensitivity to vecuronium or bromides
- Conscious or inadequately anesthetized animals
- Lack of facilities for positive pressure ventilation/mechanical ventilation
- Severe hepatic dysfunction (relative contraindication; atracurium preferred)
Adverse effects
- Profound, prolonged musculoskeletal paralysis (pharmacologic effect)
- Skeletal muscle weakness
- Respiratory arrest (if mechanical ventilation is not provided)
- Prolonged apnea (expected pharmacological effect)
- No cardiovascular effects or histamine release reported at clinical doses
Precautions
- Ventilation Required: Must only be used when facilities for intubation and mechanical ventilation are immediately available.
- Organ Dysfunction: Use with caution in patients with severe renal dysfunction. Lower doses may be necessary in patients with hepatic or biliary disease due to delayed clearance and prolonged recovery times.
- Myasthenia Gravis: Neuromuscular blocking agents should be used with extreme caution, if at all, in patients with myasthenia gravis (though one successful case in a dog has been reported).
- Pregnancy: FDA Category C. Animal studies show adverse fetal effects, but adequate human/veterinary studies are lacking. Use only if benefits outweigh risks.
- No Analgesia: Does not provide pain relief or sedation. Ensure adequate depth of anesthesia.
Drug interactions
May have a synergistic effect if used concurrently with vecuronium.
May speed the onset of action and enhance the neuromuscular blocking actions of vecuronium; do not give vecuronium until succinylcholine effects have subsided.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
May enhance or prolong the neuromuscular blocking activity.
Prolonged neuromuscular blockade
Prolonged neuromuscular blockade
Prolonged neuromuscular blockade
Monitoring
- Level of neuromuscular relaxation (using a peripheral nerve stimulator/train-of-four monitor)
- Heart rate, blood pressure, and ECG
- SpO2 and End-tidal CO2 (capnography)
- Core body temperature
- Neuromuscular function (Peripheral nerve stimulator / Train-of-Four)
- Continuous respiratory monitoring (Capnography/ETCO2, SpO2)
- Heart rate and blood pressure
- Acid-base and electrolyte status (especially potassium)
Pharmacokinetics
Half-life
Absorption
Onset of neuromuscular blockade after IV injection is dose-dependent. In dogs at 0.1 mg/kg IV, full block occurs within 2 minutes. Intratracheal administration (studied in rats) has a slower onset than IV but faster than IM, with a longer duration of action than IV.
Distribution
Distributes to the neuromuscular junction (motor endplate).
Metabolism
Partially metabolized in the liver.
Elimination
Vecuronium and its metabolites are excreted into the bile and urine. Clearance may be delayed in patients with significant renal or hepatic disease.
Overdose
No cases of vecuronium overdosage have been reported in human or veterinary medicine.
Treatment of Overdose:
- Treat conservatively with mechanical ventilation, oxygen therapy, and IV fluids until the block wears off naturally.
- Pharmacologic Reversal: Blockade can be reversed using an anticholinesterase agent (e.g., edrophonium, physostigmine, or neostigmine) combined with an anticholinergic (atropine or glycopyrrolate) to prevent severe bradycardia and excessive salivation.
- Suggested Reversal Protocol: Neostigmine 0.06 mg/kg IV administered after Atropine 0.02 mg/kg IV.
Available products
Formulations
- Powder for injection
- Injectable: 10 mg powder for reconstitution
Human-labeled
- Vecuronium Bromide Powder for Injection: 10 mg & 20 mg; in 10 mL & 20 mL vials, with and without diluent (Norcuron, generic)
- Norcuron 10 mg powder for solution for injection
Regulatory status
Available as a human POM (Prescription Only Medicine) used under the cascade.
POM. Used under the prescribing cascade.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store commercially available powder at room temperature and protect from light. After reconstitution with sterile water, it is stable for 24 hours at 2-8°C or room temperature (<30°C) in the original container. Contains no preservative; discard unused portions. Do not mix with alkaline solutions (e.g., thiobarbiturates). Physically compatible with D5W, normal saline, D5 in normal saline, and lactated Ringer's.
Client information
This medication is strictly for use by veterinary professionals in a hospital setting.
- Purpose: It is a muscle relaxant used during complex surgeries or when a patient needs to be placed on a mechanical ventilator to help them breathe.
- Safety: Your pet will be completely asleep (fully anesthetized) and unaware of their surroundings before this drug is given. Because it relaxes the breathing muscles, the veterinary team will use a machine to breathe for your pet while they are under its effects.
- Monitoring: Your pet will be continuously monitored by trained professionals until the medication wears off and they can breathe comfortably on their own.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.