Suxamethonium Chloride

Products

Suxamethonium chloride is commercially available as a solution for injection (lysthenone, succinoline). It was introduced in the 1950s and has been approved in many countries since 1954. Suxamethonium chloride is also known as succinylcholine or succinylcholine chloride, especially in English. In jargon, it is also called Suxi or Sux.

Structure and properties

Suxamethonium chloride (C14H30Cl2N2O4 – 2 H2O, Mr = 397.3 g/mol) is the diester of succinic acid (succinyl acid) with two molecules of choline. Formally, it is two molecules of acetylcholine covalently bonded together. Suxamethonium chloride exists as a white, crystalline and hygroscopic powder with a slightly bitter taste that is readily soluble in water.

Effects

Suxamethonium chloride (ATC M03AB01) has muscle relaxant properties and causes paralysis of striated skeletal muscle. It is one of the depolarizing and non-competitive muscle relaxants. Suxamethonium occupies the nicotinic acetylcholine receptors at the motor end plate instead of the natural transmitter acetylcholine and induces depolarization and excitation of the muscle fiber. It is an agonist at this receptor. Unlike acetylcholine, it is not followed by repolarization, which is why acetylcholine can temporarily de-excite the muscle. This is because suxamethonium is inactivated by butyrylcholinesterases (plasma cholinesterases) and not by tissue acetylcholinesterases. The effects occur rapidly, within one minute, and last only a few minutes unless the drug is continued.

Indications

  • For short-term muscle relaxation for intubation before surgical procedures, including obstetrics. Suxamethonium chloride is often used in rescue medicine.
  • For permanent relaxation during short procedures that require well-controlled relaxation.
  • To facilitate the reduction of fractures and dislocations.
  • To mitigate convulsions during electroshock treatment.

Dosage

According to the professional information. The drug is administered intravenously or intramuscularly.

Abuse

Suxamethonium chloride has been abused in the past for poison killings. It paralyzes respiratory muscles and causes respiratory failure. Patients containing suxamethonium chloride must therefore always receive artificial respiration.

Contraindications

For complete precautions, see the drug label.

Adverse effects

The most common possible adverse effects include:

  • Muscle pain
  • Involuntary muscle contractions (muscle twitches, called fasciculations).
  • Increase in serum potassium, hyperkalemia.
  • Cardiac arrhythmias, bradycardia (slow heartbeat).
  • Myoglobinemia (Increased myoglobin levels in the blood).
  • Increase in intraocular pressure
  • Increase in pressure in the stomach, risk of vomiting.
  • Hypersensitivity reactions, flushing