INDICATIONS     CONTRA-INDICATIONS     DOSAGE     SIDE-EFFECTS     PREGNANCY     OVERDOSE     IDENTIFICATION     PATIENT INFORMATION

Logo SUXAMETHONIUM CHLORIDE Injection Intramed.

SCHEDULING STATUS:
S4

PROPRIETARY NAME
(and dosage form):

SUXAMETHONIUM CHLORIDE Injection Intramed.

COMPOSITION:
Each 2 mL ampoule contains
Suxamethonium Chloride 100 mg.

PHARMACOLOGICAL CLASSIFICATION:
A 17.1 Peripherally-acting muscle relaxants.

PHARMACOLOGICAL ACTION:
Suxamethonium chloride is a depolarising, neuromuscular blocking agent. The initial effect is to depolarise the membrane in the same manner as acetylcholine, but more persistently, which results in a brief period of firing manifested by transient muscular fasciculation. This phase is succeeded shortly by neuromuscular paralysis, the mechanism and even the primary site of which are still uncertain and controversial.

INDICATIONS:
The main clinical use is as an adjuvant in surgical anaesthesia to obtain relaxation of skeletal muscle, particularly of the abdominal wall, so that operative manipulations are facilitated. With muscular relaxation no longer dependent upon general anaesthesia, a much lighter level of anaesthesia suffices. The drug is also of value in various orthopaedic procedures, such as the correction of dislocations and the alignment of fractures. It has also been used to advantage to facilitate laryngoscopy, bronchoscopy and oesophagoscopy, in combination with general anaesthesia.

CONTRA-INDICATIONS:
Suxamethonium chloride is contra-indicated in patients who have suffered burns, exhibit myotonia and muscular rigidity, or are known to have atypical pseudocholinesterase. Suxamethonium chloride is also contra-indicated in patients with penetrating wounds of the eye or while the globe is open, or after initial surgery in massively traumatised patients. Its use is inadvisable in patients with low serum-pseudocholinesterase concentrations such as may occur in liver disease, malnutrition, severe anaemia, and in persons exposed to organophosphate insecticides or weedkillers. Its use is also inadvisable in patients with advanced myasthenia gravis, neurological defects or phaeochromocytoma.

WARNINGS:

DOSAGE AND DIRECTIONS FOR USE:
Determined by the physician according to the patient’s needs.
U.S.P. usual dose: 20 to 80 mg intravenously; up to 2,5 mg per kg body mass intramuscularly, to a maximum of 150 mg.

SIDE-EFFECTS AND SPECIAL PRECAUTIONS:
Prolonged apnoea occurs in patients with low serum concentrations of pseudocholinesterase and in those with an atypical pseudocholinesterase. It has also been reported after high or repeated doses when a dual block has occurred. The administration of suxamethonium may be followed by bradycardia, often associated with cardiac arrhythmia; cardiac arrest has been reported. Sinus tachycardia and a rise in blood pressure has occurred after the continuous infusion of suxamethonium.

Malignant hyperpyrexia is a rare complication in patients anaesthetised with halothane and nitrous oxide or other general anaesthetic agents and has been increasingly associated with concomitant administration of suxamethonium; it occurs in subjects with musculoskeletal disorders and also in apparently healthy individuals who, it has been suggested, might be genetically predisposed to this syndrome. The symptoms are increasing hyperthermia with or without muscular hypertonicity, often fatal cardiovascular complications, severe acidosis, hyperkalaemia, and haemoglobinuria or myoglobinuria.

Hypersensitivity reactions to suxamethonium have been reported and bronchospasm has occasionally occurred. Muscular pain similar to that following strenuous exercise may occur in the immediate postoperative period, particularly in patients who are ambulant, but is is not related to dosage or the degree of fasciculation.

Myoglobinuria has been reported, either alone or associated with malignant hyperpyrexia.

Suxamethonium also causes a transient rise in intra-ocular pressure, and salivary gland enlargement. There may be some increase in bowel movements and in gastric and salivary secretions due to the muscarinic action of suxamethonium. It is not generally recommended in uraemic patients especially those with high serum-potassium concentrations. It should be used with caution in patients with cardiac disease.

Atropine should be given before administration of suxamethonium chloride to prevent excessive bradycardia, bronchial secretion, or other muscarine effects.

Administration of suxamethonium before or after the use of a non-depolarising relaxant such as tubocurarine may cause a mixed block.

The effects of suxamethonium may be enhanced by some aminoglycoside or polypeptide antibiotics administered by intraperitoneal injection, by magnesium sulphate, narcotic analgesics, procaine, propanidid, quinidine, and by a decreased body temperature. The depolarising effects of suxamethonium may also be enhanced by neostigmine and other anticholinesterases; it has been recommended that eye drops containing long-acting anticholinesterase such as ecothiopate should be discontinued at least 2 weeks before the administration of suxamethonium.

Bradycardia due to suxamethonium may be enhanced by halothane or cyclopropane but diminished or prevented by thiopentone. The effects of digitalis may be enhanced by suxamethonium, leading to cardiac arrhythmias.

KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT:
See above for symptoms. Prolonged apnoea should be treated by assisted respiration with nitrous oxide and oxygen until spontaneous respiration is fully restored.
Transfusion of fresh whole blood, frozen plasma, or another source of pseudocholinesterase will help the destruction of the suxamethonium.
Neostigmine should not be used.

Sometimes, though not always, when the action of suxamethonium is prolonged, the myoneural block ceases to be depolarising in type and acquires some features of the paralysis produced by tubocurarine, i.e. dual block. In these cases assisted respiration should be continued until spontaneous respiration begins to return. A short acting anticholinesterase such as edrophonium 10 mg may then be given intravenously. If an obvious improvement is maintained for several minutes, neostigmine, 1 to 2 mg, may be given. The immediate use of neostigmine is not advisable owing to the difficulty of determining the nature of the block.

IDENTIFICATION:
Clear solution in amber glass ampoules.

PRESENTATION:
Packs of 10 x 2 mL ampoules.

STORAGE INSTRUCTIONS:
Store in a refrigerator.
Protect from light.
KEEP ALL MEDICINES OUT OF REACH OF CHILDREN.

REGISTRATION NUMBER:
M/17.1/270

NAME AND BUSINESS ADDRESS OF APPLICANT:
INTRAMED (Pty) Ltd
6 Gibaud Road
Port Elizabeth 6001

DATE OF PUBLICATION OF THIS PACKAGE INSERT:
Dec. 1980 2-427/10-93
  KOHLER C&P P.E.

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