Suxamethonium (Succinylcholine)

Suxamethonium (Succinylcholine) In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Competitively binds to the nicotinic acetylcholine receptor.
• The persistent depolarization prevents the transmission of further action potentials, resulting in muscle relaxation.

Uses of Suxamethonium (Succinylcholine)

• Used to facilitate intubation in cats.

Dose of Suxamethonium (Succinylcholine) in Dogs and Cats

Dogs:

• Do not use.

Cats:

• 1.0 mg/kg i.v. A total dose of 3.5 mg is satisfactory in cats >3.5 kg.

Side Effects of Suxamethonium (Succinylcholine) in Dogs and Cats

• Can cause arrhythmias (sinus bradycardia, ventricular arrhythmias) via stimulation of muscarinic receptors in the sinus node.
• A small rise in potassium concentration is expected after suxamethonium; patients with burns and neuromuscular disorders are at severe risk of hyperkalaemia.

Contraindications of Suxamethonium (Succinylcholine) in Dogs and Cats

• Do not administer unless the animal is adequately anaesthetized and facilities to provide positive pressure ventilation are available.
• Do not use in animals exposed to organophosphate compounds.

Some Notes:

• The actions of suxamethonium may be enhanced by beta-adrenergic blockers (e.g. propranolol), furosemide, isoflurane, lidocaine, magnesium salts and phenothiazines.
• Diazepam may reduce the duration of action of suxamethonium.
• Neostigmine and pyridostigmine should not be administered with suxamethonium as they inhibit pseudocholinesterases, thereby enhancing suxamethonium’s effect.
• There are no indications for suxamethonium in dogs.
• Suxamethonium has a very rapid onset of action (5–15 seconds) and short duration of
  action (3–5 minutes).
• However, use of neuromuscular blockade to facilitate intubation is rarely required in small animals and suxamethonium has been largely replaced by non-depolarizing drugs.
• Use with caution in patients with hepatic disease.