Consumer medicine information

Suxamethonium Chloride Injection BP

Suxamethonium chloride


Brand name

Suxamethonium Chloride Injection BP (Solution for injection)

Active ingredient

Suxamethonium chloride




Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Suxamethonium Chloride Injection BP.

What is in this leaflet

This leaflet answers some of the common questions people ask about Suxamethonium Chloride Injection. It does not contain all the

information that is known about Suxamethonium Chloride Injection.

It does not take the place of talking to your doctor or pharmacist.

All medicines have risks and benefits. Your doctor will have weighed the risks of your being given Suxamethonium Chloride Injection against the benefits they expect it will have for you.

If you have any concerns about being given this medicine, ask your doctor or pharmacist.

Keep this leaflet.

You may need to read it again.

What Suxamethonium Chloride Injection is for

Suxamethonium Chloride Injection is used to stop your muscles moving during surgery or medical procedures.

It belongs to a group of medicines called neuromuscular blockers which work by stopping messages being sent from the nerves to the muscles.

Your doctor will have explained why you will be given Suxamethonium Chloride Injection.

Follow all directions given to you by your doctor carefully.

They may differ from the information contained in this leaflet.

Your doctor may prescribe this medicine for another use. Ask your doctor if you want more information.

Suxamethonium Chloride Injection is not addictive.

Before you are given Suxamethonium Chloride Injection

You may already have been given Suxamethonium Chloride Injection. Your doctor will have considered the situation carefully and decided to use it. However, if any of the following applies to you, tell your doctor immediately.

When you must not use it

You should not be given Suxamethonium Chloride Injection if you are pregnant or breastfeeding unless your doctor says so. Ask your doctor about the risks and benefits involved.

We do not know if it is safe for you to be given it while you are pregnant. It may affect your baby if you are given it early in pregnancy or in the last weeks before your baby is due.

Your baby may take in Suxamethonium Chloride Injection from breast milk if you are breastfeeding.

You must not be given Suxamethonium Chloride Injection if you:

  • are sensitive to suxamethonium
  • have an allergy to any ingredient listed at the end of this leaflet or any other related medicines.

If you have an allergic reaction, you may get a skin rash, hayfever, breathing difficulties or feel faint.

You should not be given Suxamethonium Chloride Injection if you have or have had the following medical conditions:

  • severe muscle stiffness and fever (malignant hyperthermia)
  • family history of malignant hyperthermia
  • muscle disease or weakness (e.g. myasthenia gravis or muscular dystrophy)
  • glaucoma (increased pressure in the eye)
  • eye injuries
  • recent paraplegia
  • kidney problems
  • severe burns
  • High blood levels of potassium
  • prolonged infections

Before you are given it

You must tell your doctor if you have any of these medical conditions:

  • heart or lung problems
  • malnutrition or severe dehydration
  • reduced red blood cells and iron stores (anaemia)
  • under-active thyroid gland
  • liver problems
  • fever
  • paraplegia
  • severe injuries
  • cancer
  • skin diseases
  • broken bones

It may not be safe for you to be given Suxamethonium Chloride Injection if you have any of these conditions.

Taking other medicines

Tell your doctor if you are taking any other medicines, including medicines that you buy at the chemist, supermarket or health food shop.

These medicines may affect the way Suxamethonium Chloride Injection works.

Some medicines and Suxamethonium Chloride Injection may interfere with each other. These include:

  • quinine
  • chloroquine, hydroxychloroquine
  • contraceptive pill
  • medicines for depression or mental illness
  • medicine for epilepsy or seizures e.g. phenytoin
  • some antibiotics
  • diuretics
  • corticosteroids
  • medicine for reflux or stomach ulcers e.g. cimetidine
  • asthma reliever medication e.g. Bricanyl®
  • medicines for high blood pressure or heart problems
  • quinidine or digoxin
  • magnesium salts
  • eye drops for glaucoma
  • some anticancer medicines
  • medicines to treat Alzheimer's disease
  • medicines to treat myasthenia gravis

These medicines may affect the way Suxamethonium Chloride Injection works.

Your doctor or pharmacist can tell you what to do if you are taking any of these medicines.

Tell your doctor if you have recently been in contact with weed killers or insecticides.

If you have not told your doctor or anaesthetist about any of these things, tell them before you are given any Suxamethonium Chloride Injection.

How Suxamethonium Chloride Injection is given

Suxamethonium Chloride Injection will be given to you by an anaesthetist. It will not be given to you until you are asleep from an anaesthetic.

It will be given by injection into your bloodstream or muscles. The dose you will be given will be carefully worked out depending on the length of the procedure, and your body weight. Children will be given reduced amounts of Suxamethonium Chloride Injection.

Since Suxamethonium Chloride Injection will stop your muscles moving, it may be necessary for the anaesthetist to help you breathe while you are being given it.


The anaesthetist giving you Suxamethonium Chloride Injection will be experienced in its use, so it will be extremely unlikely that you will be given too much.

Suxamethonium Chloride Injection doses should be carefully worked out, so problems with overdose are unlikely. There is another medicine called neostigmine which can be used if needed to reverse that effects of too much Suxamethonium Chloride Injection.

Side effects

Tell your doctor, nurse or pharmacist as soon as possible if you do not feel well after you have been given Suxamethonium Chloride Injection.

It may have unwanted side effects in a few people.

All medicines can have side effects. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor if you notice any of the following and they worry you:

  • increased saliva levels or mucous production
  • rash
  • muscle twitching or pain
  • flushing
  • itching
  • more bowel movements than normal

These are all mild side effects of Suxamethonium Chloride Injection.

Tell your doctor immediately if you notice any of the following:

  • change in heart beat or palpitations
  • eye pain
  • muscle stiffness
  • fever
  • breathing difficulties, rash or irritation
  • headache
  • feeling faint.

These are all serious side effects. You may need urgent medical attention.

Serious side effects are rare.

Tell your doctor if you notice anything else that is making you feel unwell.

Some people may get other side effects while being given Suxamethonium Chloride Injection.


Suxamethonium Chloride Injection Injection must be kept in the fridge where the temperature stays between 2 - 8 °C.

Do not freeze.


Any Suxamethonium Chloride Injection from a single dose which is not used will be disposed of in a safe manner by your doctor or nurse.

Product description

Suxamethonium Chloride Injection is a clear, colourless solution. It contains Suxamethonium Chloride Injection Chloride (dihydrate) 50 mg/mL as the active ingredient, plus:

Sodium Hydroxide or Hydrochloric Acid (E 507){for pH adjustment}

Water for Injections

Available in 2mL Polyamp DuoFit® ampoules in packs of 50.

Suxamethonium Chloride Injection is known as succinylcholine injection in the U.S.A.


AstraZeneca Pty Ltd
ABN 54 009 682 311
Alma Road

This leaflet was prepared in

October 2004.

Australian Registration Number

Suxamethonium Chloride Injection 100 mg/2mL Polyamp DuoFit® 11988

®Trade Marks herein are the property of the AstraZeneca group


Brand name

Suxamethonium Chloride Injection BP (Solution for injection)

Active ingredient

Suxamethonium chloride




1 Name of Medicine

Suxamethonium chloride.

6.7 Physicochemical Properties

The chemical name for suxamethonium chloride is 2,2'-succinyldioxybis(ethyltrimethylammonium) dichloride dihydrate.

Chemical structure.

CAS number.


2 Qualitative and Quantitative Composition

2 mL sterile solution of pH 3.0 - 5.0 containing 100 mg of suxamethonium chloride. Suxamethonium chloride is a white or almost white, crystalline powder.
Excipient with known effect: sodium hydroxide.
For the full list of excipients, see Section 6.1.

3 Pharmaceutical Form

Injection solution. Clear, colourless solution.

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

Suxamethonium is an ultrashort acting depolarising type neuromuscular blocking agent.
Suxamethonium combines with the cholinergic receptors of the motor end plate to produce depolarisation. Neuromuscular transmission is inhibited so long as an adequate concentration of suxamethonium remains at the receptor site.
Suxamethonium has no direct action on smooth muscle structures, including the uterus. Suxamethonium may produce slowing of heart rate via vagal stimulation.
When suxamethonium is administered over a prolonged period the characteristics of the neuromuscular block may change from the characteristic depolarising type to one resembling a nondepolarising block.

Clinical trials.

No data available.

5.2 Pharmacokinetic Properties


Suxamethonium has a rapid onset and a short duration of action. Following intravenous (IV) administration of a single therapeutic dose in healthy adults, complete muscle relaxation occurs within ½ to 1 minute, persists for about 2-3 minutes, and gradually dissipates within 10 minutes.
Following intramuscular (IM) administration the onset of action occurs in about 2-3 minutes, with a duration ranging from 10-30 minutes.
The duration of action is prolonged in patients with low plasma pseudocholinesterase concentration.


Suxamethonium crosses the placenta, generally in small amounts.


Plasma pseudocholinesterases hydrolyse suxamethonium to succinylmonocholine (relatively inactive) and choline. Approximately 10% of drug is excreted unchanged in the urine.

5.3 Preclinical Safety Data


No data available.


No data available.

4 Clinical Particulars

4.1 Therapeutic Indications

For the production of skeletal muscle relaxation in anaesthesia. Suited for procedures requiring only brief relaxation such as endotracheal intubation, endoscopic examinations, orthopaedic manipulations, short surgical procedures and electroconvulsive therapy.

4.3 Contraindications

Patients with a personal or familial history of malignant hyperthermia, genetically determined disorders of pseudocholinesterase, myopathies associated with elevated creatinine phosphokinase (CPK) values, Duchenne's muscular dystrophy, known hypersensitivity to suxamethonium, severe hyperkalaemia, acute narrow angle glaucoma, and the presence of penetrating eye injuries (suxamethonium may cause a slight, transient increase in intraocular pressure).
It is also contraindicated in patients after the acute phase of injury following major burns, or multiple trauma, renal impairment with a raised plasma potassium concentration, or in those with extensive muscle degeneration such as recent paraplegia and severe long lasting sepsis because such patients may become severely hyperkalaemic when given suxamethonium, resulting in cardiac arrhythmia or arrest.

4.4 Special Warnings and Precautions for Use

Suxamethonium should only be administered under strict supervision of an anaesthetist familiar with its actions, characteristics and hazards who is skilled in the management of artificial respiration and only when facilities are instantly available for endotracheal intubation and for providing adequate ventilation of the patient, including the administration of oxygen under positive pressure. Be prepared to assist or control respiration.
Suxamethonium has no effect on consciousness, pain threshold or cerebration. It should therefore only be used with adequate anaesthesia.

Malignant hyperthermia.

The abrupt onset of malignant hyperthermia, a very rare hypermetabolic process of skeletal muscle, may be triggered by suxamethonium. Early premonitory signs include muscle rigidity, tachycardia, tachypnoea unresponsive to increased depth of anaesthesia, evidence of increased oxygen requirement and carbon dioxide production, rising temperature and metabolic acidosis.
On evidence of these symptoms the anaesthetic and suxamethonium should be discontinued and supportive measures implemented including administration of oxygen, sodium bicarbonate, lowering of temperature, restoration of fluids and electrolyte balance, maintenance of adequate urinary output and administration of IV dantrolene according to a standard protocol.


Administration of suxamethonium causes an immediate rise in serum potassium. This rise is normally small but may be prolonged and exaggerated in patients taking beta-blockers.
Great caution should also be observed in patients with pre-existing hyperkalaemia or electrolyte imbalance, uraemia, hemiplegia, paraplegia, extensive burns, massive trauma, diffuse intracranial lesions (head injury, encephalitis, ruptured cerebral aneurysm), tetanus, acute anterior horn cell disease, extensive denervation of skeletal muscle due to disease or injury of the CNS, or who have degenerative neuromuscular disease and in severe long lasting sepsis. Such patients may become severely hyperkalaemic when given suxamethonium, resulting in cardiac arrhythmia or arrest (see Section 4.3 Contraindications).
With burns or trauma the period of greatest risk is from about 10-90 days after the injury, but may be prolonged further if there is delayed healing or persistent infection. These patients may still react abnormally to suxamethonium 2 years after the injury. In neuromuscular disease the greatest risk period is usually from 3 weeks to 6 months after onset, but severe hyperkalaemia may occur after 24 to 48 hours or later than 6 months. Patients with severe sepsis for more than a week should be considered at risk of hyperkalaemia and suxamethonium should not be given until the infection has cleared.

Hyperkalaemia rhabdomyolysis.

There is a risk of cardiac arrest from hyperkalaemia due to rhabdomyolysis, particularly in male patients with muscular dystrophy.

Low plasma pseudocholinesterase.

Recovery from suxamethonium may occasionally be delayed possibly due to a low serum pseudocholinesterase level, this may occur in patients suffering from severe liver disease, cancer, malnutrition, severe dehydration, collagen diseases, severe anaemia, myxoedema, burns, pregnancy and the puerperium, severe infections, myocardial infarction, renal impairment and abnormal body temperature.
Also, exposure to neurotoxic insecticides or weed killers, antimalarial or anticancer drugs, monoamine oxidase (MAO) inhibitors, contraceptive pill, pancuronium, chlorpromazine, ecothiopate or neostigmine may result in low levels of pseudocholinesterase.
Suxamethonium should be administered with extreme caution and in reduced doses in such patients. If low pseudocholinesterase concentration is suspected, slow administration of a small test dose of suxamethonium (5-10 mg as a 0.1% solution) should be considered.

Antidysrhythmic drugs.

Suxamethonium should be administered with great caution in patients receiving quinidine and those who have been digitalised or who may have digitalis toxicity. In these circumstances the rise in serum potassium due to suxamethonium may possibly cause arrhythmias.

Delayed recovery.

When recovery from suxamethonium is delayed, assisted respiration sufficient for full oxygenation, yet avoiding excessive elimination of carbon dioxide, should be maintained until paralysis ceases. This should be combined with light narcosis, e.g. nitrous oxide/ oxygen mixture.
Neostigmine should not be given when prolonged apnoea follows a single dose of suxamethonium. Neostigmine and other anticholinesterase drugs may have the effect of intensifying the depolarisation block caused by suxamethonium.

Nondepolarising blockade.

If suxamethonium is given repeatedly or over a prolonged period the depolarising block may change to one with characteristics of a nondepolarising block. This may be associated with prolonged respiratory depression and apnoea. Following a positive diagnosis of a nondepolarising blockade, the administration of neostigmine preceded by atropine may be considered.

Debilitated patients.

Use with caution in patients who are hypoxic or those who have cardiovascular, hepatic, pulmonary, metabolic or renal disorders or myasthenia gravis. The action of suxamethonium may be altered in these patients. Its use is not advisable in patients with phaeochromocytoma. As suxamethonium produces muscle contractions before relaxation it should be used with caution in patients with bone fractures.
Suxamethonium should be avoided in patients with myotonias, as response is unpredictable.

Use in eye surgery.

Suxamethonium causes a slight transient increase in intraocular pressure immediately after injection and during the fasciculation phase. It should therefore be used cautiously if at all during intraocular surgery and in patients with glaucoma.

Use in hepatic impairment.

Use with caution in patients who have hepatic disorders. The action of suxamethonium may be altered in these patients.

Use in renal impairment.

Use with caution in patients who have renal disorders. The action of suxamethonium may be altered in these patients. Patients with impaired renal function may occasionally experience prolonged apnoea due to accumulation of succinylmonocholine.

Use in the elderly.

No data available.

Paediatric use.

Neonates and premature infants may be relatively resistant to suxamethonium.
Intravenous bolus in children may result in profound bradycardia or on occasion, asystole. This tends to be more common after a second dose. Pretreatment with atropine can reduce the risk of bradycardia.

Effects on laboratory tests.

No data available.

4.5 Interactions with Other Medicines and Other Forms of Interactions

Coadministration of inhaled anaesthetics (cyclopane, diethylether, halothane and nitrous oxide) may increase the incidence of dysrhythmias (especially bradycardia), apnoea and the occurrence of malignant hyperthermia in susceptible persons. Inhaled anaesthetics have little effect on the usual depolarising neuromuscular blockade of suxamethonium but may enhance the phase II block (nondepolarising) that may be produced by repeated dosage of suxamethonium. Severe bradycardia and asystole have occurred when suxamethonium is used in anaesthetic regimens with propofol and opioids such as fentanyl.
Drugs which may enhance or prolong the effects of suxamethonium include lignocaine, procaine, oxytocin, oral contraceptives, some nonpenicillin antibiotics (streptomycin, neomycin, kanamycin, capreomycin, tobramycin, framycetin, amikacin, gentamicin, colistin and polymyxins), tacrine, beta-adrenergic blockers, trimethaphan, phenelzine, aprotinin, quinidine, promazine, lithium carbonate, phenytoin, carbamazepine, magnesium salts, quinine, chloroquine, cimetidine, terbutaline sulfate, high dose corticosteroids and cytostatic agents such as cyclophosphamide, thiotepa and azathioprine, selective serotonin reuptake inhibitors. Diazepam may reduce the duration of neuromuscular blockade produced by suxamethonium.
Amphotericin B and thiazide diuretics may increase the effects of suxamethonium secondary to induced electrolyte imbalance. Patients with hypokalemia or hypocalcaemia require reduced doses of suxamethonium.
Inhibitors of plasma cholinesterases such as neostigmine, pyridostigmine bromide, rivastigmine, donepezil, metoclopramide, physostigmine and phospholine iodide can considerably prolong the depolarising action of suxamethonium. It is recommended that long acting anticholinesterase inhibitor (ecothiopate) eye drops should be discontinued several months prior to administration of suxamethonium.
Administration of suxamethonium prior to or with a nondepolarising muscle relaxant, e.g. pancuronium, mivacurium can alter the intensity and/or duration of neuromuscular blockade.
Simultaneous administration of suxamethonium and atracurium significantly reduces the duration of suxamethonium.
Concomitant digoxin or verapamil, and suxamethonium therapy has been reported to result in cardiac arrhythmias.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

No data available.
(Category A)
Safety of the use of suxamethonium in pregnancy has not been established with respect to effects on foetal development. Therefore, suxamethonium should not be administered to pregnant women unless the potential benefit outweighs the possible hazards.
Plasma pseudocholinesterase levels are decreased in pregnancy and several days postpartum by approximately 25%, therefore a high proportion of these patients may be expected to show prolonged apnoea.
Suxamethonium crosses the placenta, but generally only in small amounts. Residual neuromuscular blockade may occasionally occur in the neonate after repeated high doses of suxamethonium to the mother during delivery by caesarean section.
No data available.

4.8 Adverse Effects (Undesirable Effects)

The following adverse reactions have been reported following administration of suxamethonium.


Postoperative muscle pain, muscle fasciculation, rhabdomyolysis, myoglobinuria, myoglobinaemia, elevated creatine phosphokinase, hypertonia, trismus.


Bradycardia, tachycardia, arrhythmias, cardiac arrest, hypertension, hypotension, tachyphylaxis, ventricular fibrillation as a result of hyperkalaemia.


Apnoea, prolonged respiratory failure, bronchospasm, increased bronchial secretions, pulmonary oedema in infants.

Endocrine, metabolic.

Malignant hyperthermia, porphyria, hyperkalaemia, excessive salivation.


Increased intragastric pressure, increased bowel movements, increased gastric secretions, possible aspiration.

Special senses.

Increased intraocular pressure.


Rise in intracranial pressure, renal failure, precipitation or exacerbation of myasthenia gravis.
Hypersensitivity reactions including circulatory collapse, flushing, rash, urticaria, bronchospasm and shock, which may lead to death.

Reporting of suspected adverse reactions.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at

4.2 Dose and Method of Administration

Dosage is individualised and its administration should be determined after careful assessment of the patient. The dose of suxamethonium is dependent on bodyweight, the degree of muscle relaxation required and the response of individual patients. Suxamethonium causes paralysis of the respiratory muscles, therefore after administration, respiration must be controlled. It should not be administered to a conscious patient.
Suxamethonium should not be mixed with any neuromuscular blocking agent, nor with general anaesthetics such as short acting barbiturates, nor any other therapeutic agent in the same syringe.
Suxamethonium Chloride Injection contains no antimicrobial agent. It should be used only once and any residue discarded.
An initial test dose of 0.1 mg/kg may be given intravenously to determine the patient's response.


For short procedures, such as endotracheal intubation the usual adult dose is 0.6 mg/kg (range 0.3-1.1 mg/kg) administered IV over 10 to 30 seconds. This dose produces muscle relaxation in about 60 seconds and has a duration of approximately 4 to 6 minutes. Larger doses produce more prolonged muscle relaxation.
For more prolonged surgical procedures in an adult, suxamethonium is commonly given by IV infusion at a rate of 2.5-4.3 mg/minute. When given by intravenous infusion, suxamethonium should be diluted to 0.1 to 0.2% (1-2 mg/mL) in 5% dextrose solution or sterile isotonic saline.


Neonates and premature infants may be relatively resistant to suxamethonium.
The usual paediatric IV dose is 1 to 2 mg/kg. If necessary, additional doses may be administered in accordance with the patient's response. Continuous IV infusions of suxamethonium are considered unsafe in neonates and children because of the risk of inducing malignant hyperthermia.
Intravenous bolus in children may result in profound bradycardia or on occasion asystole. This tends to be more common after a second dose. Pretreatment with atropine can reduce the risk of bradycardia.
When a suitable vein is inaccessible, suxamethonium may occasionally be given by intramuscular injection. A suggested IM dose for adults and children may be up to 2.5 mg/kg but the total dose should not exceed 150 mg.
Diluted solutions of suxamethonium must be used within 24 hours of preparation. Discard unused solutions.

4.7 Effects on Ability to Drive and Use Machines

The effects of this medicine on a person's ability to drive and use machines were not assessed as part of its registration.

4.9 Overdose

For information on the management of overdose, contact the Poison Information Centre on 131126 (Australia).
The most serious effects of overdosage are apnoea and prolonged muscle paralysis. It is essential to maintain the airway and adequate ventilation until spontaneous respiration is fully restored.
The use of neostigmine to reverse a nondepolarising block is a clinical decision which depends on the subject, the experience, and the judgment of the clinician. If neostigmine is used, its administration should be accompanied by an appropriate dose of atropine.

7 Medicine Schedule (Poisons Standard)


6 Pharmaceutical Particulars

6.1 List of Excipients

Water for injections.
Sodium hydroxide and/or hydrochloric acid for pH adjustment.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store between 2°-8°C. Refrigerate. Do not freeze.

6.5 Nature and Contents of Container

2 mL polyethylene ampoules (Polyamp DuoFit) in packs of 50.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

Summary Table of Changes