Atracurium: veterinary dose and monograph

At a glance

Drug class

Veterinary drug

Also known as

Tracrium, Atracurium besylate

Species with doses

Dogs, Cats, Horses and Rabbits

General dose range

0.2–0.5 mg/kg IV bolus then CRI/top-ups (to effect) — check the species tables for the indication

Routes

IV

Last reviewed

1 October 2026

Indications

• Skeletal-muscle relaxation during general anaesthesia (intra-ocular, intra-thoracic, abdominal, orthopaedic surgery)
• Facilitation of mechanical ventilation / controlled ventilation
• Patients with hepatic or renal impairment needing a neuromuscular blocker (organ-independent elimination)

Atracurium dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Dogs

• Neuromuscular blockade (intra-op): Papich 5e: 0.2 mg/kg IV initially, then 0.15 mg/kg q30min. Plumb’s p.125: 0.2 mg/kg IV then 0.1 mg/kg no more often than every 20–30 min without a nerve stimulator (Spelts); 0.25 mg/kg to facilitate intubation (Crowe); ventilated patients 0.2–0.5 mg/kg load (Dhupa). Deep anaesthesia and positive-pressure ventilation are mandatory; reverse with neostigmine or edrophonium plus an anticholinergic.
• Neuromuscular blockade — CRI: Papich 5e: 0.3–0.5 mg/kg IV load then 4–9 µg/kg/min. Plumb’s p.125 (Dhupa 2005): 0.2–0.5 mg/kg load, then 3–9 µg/kg/min starting 5 min later, in D5W or saline; do not mix with other drugs. Ventilate and monitor.

Cats

• Neuromuscular blockade (intra-op): Papich 5e (dogs and cats): 0.2 mg/kg IV then 0.15 mg/kg q30min; CRI 0.3–0.5 mg/kg load then 4–9 µg/kg/min. Plumb’s p.125: induction 0.22 mg/kg IV with a 1/10–1/6 priming dose given 4–6 min earlier; intra-operative 0.11 mg/kg IV (Mandsager); 0.2 mg/kg then 0.1 mg/kg (Spelts). Ventilation and neuromuscular monitoring are mandatory.

Horses

• Neuromuscular blockade (specialist): Papich 5e: 0.05–0.07 mg/kg IV. Plumb’s p.125 (Mandsager 1988): 0.055 mg/kg IV intra-operatively. Full ventilatory support and monitoring required. ARCI Class 2.

Rabbits

• Paralysis for peri-ophthalmic surgery: Plumb’s p.125 (Ivey & Morrisey 2000): rabbits 0.1 mg/kg. Requires ventilation.

Contraindications

Use without the ability to mechanically ventilate and monitor neuromuscular function. Inadequate anaesthesia (awareness/paralysis is catastrophic — it has no anaesthetic/analgesic effect). Myasthenia gravis (profound, prolonged block). Known hypersensitivity (histamine release). Without trained anaesthesia personnel/equipment.

Adverse effects

• Histamine release (hypotension, flushing, bronchospasm) — dose/rate-related
• Prolonged paralysis if overdosed or with potentiating drugs
• No sedation/analgesia (awareness risk if anaesthesia inadequate)
• Laudanosine metabolite (CNS-stimulant at very high cumulative doses — rarely relevant)

Drug interactions

• Volatile anaesthetics, aminoglycosides, polymyxins, magnesium: POTENTIATE and prolong the block
• Anticholinesterases (neostigmine, edrophonium): REVERSE the block (give with an anticholinergic)
• Hypothermia/acidosis: slow Hofmann elimination (prolonged block)
• Other neuromuscular blockers: additive

Pregnancy and lactation

Does not readily cross the placenta (quaternary compound); used in anaesthesia when needed with full support.

Monitoring

• NEUROMUSCULAR monitoring (train-of-four) — essential to titrate and confirm recovery
• Mechanical ventilation / capnography / SpO2 (the diaphragm is paralysed)
• Depth of anaesthesia (NO awareness — it provides no anaesthesia/analgesia)
• Blood pressure (histamine release); temperature (affects offset)

Toxicity and overdose

The "toxicity" is its intended, dangerous pharmacology — total skeletal-muscle paralysis including respiratory muscles with NO anaesthesia. Overdose/potentiation causes prolonged paralysis; rapid administration causes histamine-mediated hypotension/bronchospasm. Awareness under paralysis (inadequate anaesthesia) is a catastrophic risk.

Management: Continue mechanical VENTILATION and maintain anaesthesia until the block resolves (Hofmann elimination is reliable). Reverse residual block with neostigmine + glycopyrrolate guided by train-of-four. Treat histamine reactions (fluids, antihistamine, manage bronchospasm). Ensure adequate depth of anaesthesia throughout.

Clinical pearls

• The neuromuscular blocker for ORGAN-COMPROMISED patients — Hofmann elimination means predictable offset regardless of liver/kidney function
• It PARALYSES but does NOT anaesthetise — the patient must be deeply anaesthetised AND mechanically ventilated, with train-of-four monitoring; awareness under paralysis is a catastrophe
• Reverse residual block with neostigmine + an anticholinergic (glycopyrrolate) once recovery starts
• Refrigerate it (it self-degrades), give slowly to limit histamine release, and remember volatile agents/aminoglycosides/magnesium prolong the block

Mechanism of action

A non-depolarising (competitive) neuromuscular blocker that competes with acetylcholine for nicotinic receptors at the motor end-plate, preventing depolarisation and causing flaccid skeletal-muscle paralysis without initial fasciculation. Uniquely, it is eliminated by spontaneous, temperature- and pH-dependent Hofmann degradation (and ester hydrolysis), independent of hepatic/renal function — giving predictable offset even in organ failure. Reversal is achieved with an anticholinesterase (neostigmine) once spontaneous recovery begins.

Formulations and products

• Injection 10 mg/mL
• Tracrium / Atracurium — 10 mg/mL injection, Injection (refrigerate) (human-label)

Storage

Injection: REFRIGERATE (2–8 °C), protect from light; potency declines at room temperature (Hofmann degradation). Use promptly once warmed.

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

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Frequently asked questions