Neuromuscular blockers (atracurium / pancuronium / rocuronium)

What is this medication for?

• Muscle relaxation adjunct to general anesthesia (surgery, mechanical ventilation, facilitation of endotracheal intubation); paralyzing critically ill patients who tolerate minimal/no inhalant anesthesia

How is it given?

This medication is normally given by your veterinary team (in clinic or hospital).

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Pancuronium: unusually fast heart rate, ↑BP, hypersalivation (anticholinergic pre-treat) (Expected profile)

Worth a phone call to your veterinarian

• Histamine release (atracurium < tubocurarine; pancuronium rare) (Hypotension/hypersensitivity)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Apnea/respiratory paralysis — by design: ventilation mandatory (Absolute requirement)
• Prolonged weakness (overdose/repeat dosing, renal failure + pancuronium) (Monitoring-driven)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Pancuronium in renal failure (atracurium instead); unusually fast heart rate-sensitive patients (pancuronium); peripheral nerve stimulator monitoring recommended

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Aminoglycosides, magnesium, lidocaine, inhalants
  • Anticholinesterases (neostigmine 0.06 mg/kg into a vein after atropine 0.02 mg/kg, edrophonium)
  • Azathioprine
  • Succinylcholine

Storage and handling

Refrigeration per label (rocuronium stable in aqueous solution — fridge); anesthesiologist-administered only.

Good to know

• The cardinal rule: paralytic ≠ anesthetic — unconsciousness and analgesia must be independently provided; the paralyzed-awake patient is the catastrophe this class can create.
• Drug-picking logic: renal/hepatic failure → atracurium (organ-independent clearance); tachydysrhythmia risk → avoid pancuronium (vagolytic); need it FAST (RSI) → rocuronium.
• Reversal ritual: atropine FIRST (0.02 mg/kg into a vein), then neostigmine (0.06 mg/kg into a vein) — cholinesterase inhibition floods muscarinic receptors too; the anticholinergic pre-dose prevents unusually slow heart rate/salivation crisis.
• Train-of-four monitoring replaces clock-guessing — especially q20–30 min dosing limits in critical patients.