NationMaster - Encyclopedia: Suxamethonium chloride

Suxamethonium chloride (also known as succinylcholine, scoline, or SUX) is a white crystalline substance, it is odourless and highly soluble in water. The compound consists of two acetylcholine molecules that are linked by their acetyl groups. Suxamethonium is sold under several trademark names such as Anectine®, and may be referred to as "sux" for short. In pharmacology and toxicology, a route of administration is the path by which a drug, fluid, poison or other substance is brought into contact with the body 1. ... Intravenous therapy or IV therapy is the administration of liquid substances directly into a vein. ... The chemical compound acetylcholine, often abbreviated as ACh, was the first neurotransmitter to be identified. ... Acetyl is the radical of acetic acid. ... A trademark or trade mark[1] is a distinctive sign of some kind which is used by an individual, business organization or other legal entity to uniquely identify the source of its products and/or services to consumers, and to distinguish its products or services from those of other entities. ...

Suxamethonium acts as a depolarizing muscle relaxant. It imitates the action of acetylcholine at the neuromuscular junction, but it is not degraded by acetylcholinesterase but by pseudocholinesterase, a plasma cholinesterase. This hydrolysis by pseudocholinesterase is much slower than that of acetylcholine by acetylcholinesterase. A muscle relaxant is a drug which decreases the tone of a muscle. ... The chemical compound acetylcholine, often abbreviated as ACh, was the first neurotransmitter to be identified. ... In biochemistry, cholinesterase is a term which refers to one of the two enzymes (EC 3. ... Categories: Biochemistry stubs | EC 3. ...

Phase 1 block

There are two phases to the blocking effect of suxamethonium. The first is due to the prolonged stimulation of the acetylcholine receptor results first in disorganized muscle contractions (fasciculations, considered to be a side effect as mentioned below), as the acetylcholine receptors are stimulated. On stimulation, the acetylcholine receptor becomes a general ion channel, so there is a high flux of potassium out of the cell, and of sodium into the cell, resulting in an endplate potential less than the action potential. So, after the initial firing, the cell remains refractory. An acetylcholine receptor (abbreviated AChR) is an integral membrane protein that responds to the binding of the neurotransmitter acetylcholine. ... A fasciculation (or muscle twitch) is a small, local, involuntary muscle contraction (twitching) visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle fibres. ...

Phase 2 block

On continued stimulation, the acetylcholine receptors become desensitised and close. This means that new acetylcholine signals do not cause an action potential; and the continued binding of suxamethonium is ignored. This is the principal anaesthetic effect of suxamethonium, and wears off as the suxamethonium is degraded, and the acetylcholine receptors return to their normal configuration. The side effect of hyperkalaemia is because the acetylcholine receptor is propped open, allowing continued flow of potassium ions into the extracellular fluid. A typical increase of potassium ion serum concentration on administration of suxamethonium is 0.5 mmol per litre, whereas the normal range of potassium is 3.5 to 5 mmol per litre: a significant increase which results in the other side-effects of ventricular fibrillation due to reduced to action potential initiation in the heart.

Medical uses

Its medical uses are limited to short-term muscle relaxation in anesthesia and intensive care, usually for facilitation of endotracheal intubation. Despite its many undesired effects on the circulatory system and skeletal muscles (including malignant hyperthermia, a rare but life-threatening disease), it is perennially popular in emergency medicine because it arguably has the fastest onset and shortest duration of action of all muscle relaxants. Both are major points of consideration in the context of trauma care, where paralysis must be induced very quickly and the use of a longer-acting agent might mask the presence of a neurological deficit. Intubation being practiced on a dummy (conventional technique using a laryngoscope) In medicine, intubation is the placement of a tube into an external or internal orifice of the body. ... Malignant hyperthermia (MH or MHS for malignant hyperthermia syndrome, or malignant hyperpyrexia due to anesthesia) is a life-threatening condition resulting from a genetic sensitivity of skeletal muscles to volatile anaesthetics and depolarizing neuromuscular blocking drugs that occurs during or after anaesthesia. ...

A single intravenous dose of 1.0 to 1.5 milligrams per kilogram of body weight for adults or 2.0 milligrams per kilogram for pediatrics will cause flaccid paralysis within a minute of injection. For intramuscular injection higher doses are used and the effects last somewhat longer. Suxamethonium is quickly degraded by plasma cholinesterase and the duration of effect is usually in the range of a few minutes. When plasma levels of cholinesterase are greatly diminished or an atypical form of cholinesterase is present (an otherwise harmless inherited disorder), paralysis may last much longer. Acetylcholinesterase In biochemistry, cholinesterase is a term which refers to one of the two enzymes: Acetylcholinesterase (EC 3. ...

Side effects

Side effects include fasciculations, muscle pains, acute rhabdomyolysis with hyperkalemia, transient ocular hypertension, and changes in cardiac rhythm including bradycardia, cardiac arrest, and ventricular dysrhythmias. In children with unrecognized neuromuscular diseases, a single injection of succinylcholine can lead to massive release of potassium from skeletal muscles with cardiac arrest. A fasciculation (or muscle twitch) is a small, local, involuntary muscle contraction (twitching) visible under the skin arising from the spontaneous discharge of a bundle of skeletal muscle fibres. ... Rhabdomyolysis is the breakdown of skeletal muscle due to injury, either mechanical, physical or chemical. ... Hyperkalemia is an elevated blood level (above 5. ... Ocular hypertension (OHT) is intraocular pressure higher than normal in the absence of optic nerve damage or visual field loss . Current consensus in ophthalmology defines normal introcular pressure (IOP) as that between 10 mmHg and 21 mmHg . Elevated IOP is the most important risk factor for glaucoma, so those with... Bradycardia, as applied in adult medicine, is defined as a heart rate of under 60 beats per minute, though it is seldom symptomatic until the rate drops below 50 beat/min [1]. It is also less commonly known as brachycardia. ... Ventricular fibrillation (V-fib or VF) is a cardiac condition which consists of a lack of coordination of the contraction of the muscle tissue of the large chambers of the heart that eventually leads to the heart stopping altogether. ...

Succinylcholine does not produce unconsciousness or anesthesia, and its effects may cause considerable psychological distress while simultaneously making it impossible for a patient to communicate. For these reasons, administration of the drug to a conscious patient is strongly contraindicated, except in necessary emergency situations.

This drug has occasionally been used as a paralyzing agent for executions by lethal injection, although pancuronium bromide is the preferred agent today because of its longer duration of effect and its absence of fasciculations as a side effect. It has also been used for murder.[1] Lethal injection involves injecting a person with fatal doses of drugs to cause death. ... Pancuronium bromide is a chemical compound, used in medicine with the brand name Pavulon® (Organon Pharmaceuticals). ...

Succinylcholine is the drug that is suspected to have been used to murder Nevada State Controller Kathy Augustine. And that of the UN weapons inpector Dr. David Kelly. Kathy Augustine Kathy Augustine (May 29, 1956 - July 11, 2006) was a U.S. Republican Party politician from Nevada. ... For other persons named David Kelly, see David Kelly (disambiguation). ...

External links

Categories: Pages needing expert attention | Wikipedia articles needing factual verification | Lethal injection components | Muscle relaxants | Nicotinic agonists | Quaternary ammonium compounds A muscle relaxant is a drug which decreases the tone of a muscle. ... A section of the Anatomical Therapeutic Chemical Classification System. ... Alcuronium is a peripherally acting muscle relaxant in the curare alkaloid family. ... Atracurium is a neuromuscular-blocking drug or muscle relaxant in the category non-depolarising neuromuscular blocking agents, used in anaesthesia to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. ... Cisatracurium is a muscle relaxant in the quaternary ammonium compound family. ... Doxacurium chloride is a muscle relaxant in the quaternary ammonium compound family. ... Gallamine is a non-depolarising muscle relaxant. ... Mivacurium is a short-acting bisbenzylisoquinolinium based neuromuscular blocker or muscle relaxant used to facilitate intubation and relax skeletal muscles as an adjunct to general anesthesia. ... Pancuronium bromide is a chemical compound, used in medicine with the brand name Pavulon® (Organon Pharmaceuticals). ... Rocuronium is a non-depolarizing (that is, it does not cause initial stimulation of muscles before weakening them) neuromuscular blocker used in modern anaesthesia, to aid and enable endotracheal intubation, which is often necessary to assist in the controlled ventilation of unconscious patients during surgery and sometimes in intensive care. ... Suxamethonium chloride (also known as succinylcholine, or scoline) is a white crystalline substance, it is odourless and highly soluble in water. ... Tubocurarine chloride is a competitive neuromuscular blocker, used to paralyse patients undergoing anaesthesia. ... Vecuronium Bromide is a muscle relaxant in the category of non depolarising neuromuscular blocking agents. ... Baclofen (brand names KemstroÂ® and LioresalÂ®) is a derivative of gamma-aminobutyric acid, and is an agonist specific to mammalian but not fruit fly (Drosophila) GABAB receptors[1][2]. It is used for the treatment of spastic movement, especially in instances of spinal cord injury, spastic diplegia and multiple sclerosis. ... Carisoprodol is a skeletal muscle relaxant whose active metabolite is meprobamate. ... Chlormezanone is a centrally acting muscle relaxant. ... This page meets Wikipedias criteria for speedy deletion. ... Cyclobenzaprine is a skeletal muscle relaxant and a central nervous system (CNS) depressant. ... Mephenesin is a centrally acting muscle relaxant. ... Methocarbamol (chemical formula: ) is a central muscle relaxant for skeletal muscles, used to treat spasms. ... Orphenadrine is an anticholinergic drug invented in 1951 in France and made in the United States and Canada by Parke-Davis and other companies including 3M, The drug is a skeletal muscle relaxant which also has antihistamine, antispasmodic, analgesic, and local anaesthetic actions. ... Phenprobamate is a centrally acting skeletal muscle relaxant. ... Tetrazepam, (Clinoxan, Myolastan, Musaril) is a benzodiazepine derivative with anxiolytic and muscle relaxant properties. ... Tizanidine (Zanaflex) is a centrally acting a2-adrenergic agonist. ... Tolperisone. ... Dantrolene sodium is a muscle relaxant that is currently the only specific and effective treatment for malignant hyperthermia. ...

Contents

Phase 1 block

Phase 2 block

Medical uses

Side effects