Last reviewed 01/2018

Suxamethonium is a depolarising neuromuscular blocker producing a rapid (1-2 minutes), complete and predictable relaxation of skeletal muscle. Its effect normally lasts 3-5 minutes. It is used for emergency intubation - passage of endotracheal tube.

It has many side-effects or rare complications:

  • arrhythmias
  • bradycardia:
    • especially in children after repeated use
    • requires a dose of atropine before administration of a second injection in the same patient
  • hyperkalaemia:
    • 0.5-1.0 mmol/l rise in plasma potassium
    • dangerous rises reported in certain cases, e.g. burns, rhabdomyolysis
  • increased intraocular pressure
  • increased salivation
  • myotonia
  • painful fasciculation on injection - give after start of induction
  • anaphylaxis
  • malignant hyperthermia
  • rarely, atypical pseudocholinesterase enzyme results in slow breakdown of suxamethonium; blockade may last for hours