Suxamethonium / Succinylcholine
- IV / IMSuxamethonium / Succinylcholine
- Mechanism of Action
- Composed of two acetylcholine molecules joined at the acetate methyl group.
- Bind to nicotinic receptors, resulting in depolarization with opening of voltage-gated channels and muscle contraction. Voltage-gated sodium channels then close and are inactivated, while the membrane remains depolarized.
- Suxamethonium is not metabolized by acetylcholinesterase and therefore membrane depolarization is prolonged, resulting in prolonged inactivation of sodium channels and muscle relaxation.
- As the membrane remains depolarized, no further acetylcholine molecules are able to produce further depolarization.
- Pharmacology
- Ultra short-acting
- Onset 30-60 seconds
- Duration 10 minutes
Clinical Use
- Indications
- Relaxation of skeletal muscle for periods of brief anaesthesia such as for:
- Endotracheal intubation
- Endoscopy
- Orthopaedic manipulation
- Short surgical procedures
- Electroconvulsive therapy
- Contraindications
- Myopathies - including muscular dystrophy and rhabdomyolysis
- Past history of malignant hyperthermia
- Acute burns / multitrauma
- Hyperkalaemia
- Adverse Effects
- Hypersensitivity reactions - rash, flushing, anaphylaxis
- Bradycardia
- Hyperkalaemia
- Raised intracranial, intraabdominal and intraocular pressures
- Muscle pain / weakness
- Rhabdomyolysis
- Malignant hyperthermia