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Suxamethonium Chloride 50mg/ml
Solution for Injection
Suxamethonium Chloride 50mg/ml.
Each 2ml ampoule contains 100mg of
Suxamethonium Chloride.
Solution for Injection.
Clear, colourless solution.
Therapeutic indications
Used in anaesthesia as a muscle relaxant
to facilitate endotracheal intubation,
mechanical ventilation and a wide range of
surgical and obstetrics procedures.
It is also used to reduce the intensity of
muscular contractions associated with
pharmacologically or electrically - induced
Posology and method of administration
Usually by bolus injection
Adults and Children over 12 years:
The dose is dependent on body weight, the
degree of muscular relaxation required, the
route of administration, and the response
of individual patients.
To achieve endotracheal intubation
Suxamethonium Chloride is usually
administered intravenously in a dose of
1mg/kg. This dose will usually produce
muscular relaxation in about 30 to 60
seconds and has a duration of action
of about 2 to 6 minutes. Larger doses
will produce more prolonged muscular
relaxation, but doubling the dose does
not necessarily double the duration of
relaxation. Supplementary doses of
Suxamethonium Chloride of 50% to 100%
of the initial dose administered at 5 to
10 minute intervals will maintain muscle
relaxation during short surgical procedures
performed under general anaesthesia.
For prolonged surgical procedures
Suxamethonium Chloride may be given
by intravenous infusion as a 0.1% to 0.2%
solution, diluted in 5% glucose solution
or sterile isotonic saline solution, at a rate
of 2.5 to 4mg per minute. The infusion
rate should be adjusted according to the
response of individual patients.
The total dose of Suxamethonium Chloride
given by repeated intravenous injection
or continuous infusion should not exceed
500mg per hour.
Children, 1 to under 12 years:
1-2mg/kg by intravenous injection.
Suxamethonium Chloride may be given
intramuscularly to children at doses up to
4mg per kg. A total dose of 150mg should
not be exceeded.

Infants, under 1 year:
2mg/kg by intravenous injection.
Suxamethonium Chloride may be given
intramuscularly to infants at doses of up
to 4 to 5mg per kg. A total dose of 150mg
should not be exceeded.
As for adults.
The elderly may be more susceptible to
cardiac arrhythmias, especially if digitalislike drugs are also being taken. See also
Special Warnings and Precautions for Use.
Suxamethonium has no effect on the level
of consciousness and therefore should not
be administered to a patient who is not fully
Suxamethonium should not be
administered to patients who are known to
be hypersensitive to the drug.
Suxamethonium is contraindicated
in patients with a personal or family
history of malignant hyperthermia and
if the condition occurs unexpectedly,
all anaesthetic agents known to be
associated with its development including
Suxamethonium must be discontinued
straight away. Full supportive measures
must be employed immediately.
Intravenous dantrolene sodium is
indicated in the treatment of malignant
Suxamethonium is contraindicated
in patients with an inherited atypical
cholinesterase activity.
An acute transient rise in serum potassium
often occurs following the administration of
Suxamethonium in normal individuals; the
magnitude of this rise is of the order of 0.5
mmol/litre. In certain pathological states or
conditions, this increase in serum potassium
following suxamethonium administration
may be excessive and cause serious cardiac
arrhythmias and cardiac arrest. For this
reason the use of suxamethonium is contraindicated in:
• Patients recovering from major trauma,
or severe burns; the period of greatest
risk of hyperkalaemia is from about 5
to 70 days after injury and may be
further prolonged if there is delayed
healing due to persistent infection.
• Patients with neurological deficits
involving spinal cord injury, peripheral
nerve injury or acute muscle wasting
(upper and/or lower motor neurone
lesions); the potential for potassium
release occurs within the first 6 months
after the acute onset of the
neurological deficit and correlates with
the degree and extent of muscle
paralysis. Patients who have been
immobilised for prolonged periods of
time may be at similar risk.

• Patients with pre-existing
hyperkalaemia. If there is no
hyperkalaemia or neuropathy then renal
failure is not a contraindication to the
administration of a normal single
dose of Suxamethonium Injection,
but multiple or large doses may cause
clinically significant rises in serum
potassium and should not be used.
Suxamethonium causes a slight transient
rise in intra-ocular pressure and is therefore
contraindicated in the presence of open
eye injuries unless the potential benefit
outweighs the potential risk to the eye.
Suxamethonium is contraindicated in
patients with congenital myotonic diseases
such as myotonia congenita and dystrophia
myotonica as it is associated with rigidity
and severe spasms.
Suxamethonium is contraindicated
in patients with Duchenne muscular
dystrophy since its administration
may be associated with cardiac
arrest, hyperkalaemia, hyperthermia,
myoglobinaemia, post-operative
respiratory depression and rigidity.
Special warnings and precautions for use
Suxamethonium should be administered
under the supervision of an anaesthetist
familiar with it and who is skilled in the
management of artificial respiration and
only where there are adequate facilities for
immediate endotracheal intubation with
administration of oxygen by intermittent
positive pressure ventilation.
The patient must be monitored fully
with a peripheral nerve stimulator
during prolonged administration of
suxamethonium in order to avoid
Intensified and prolonged neuromuscular
blockade following Suxamethonium
Injection may occur secondary to
reduced plasma cholinesterase activity
in the following states: - pregnancy,
abnormal plasma cholinesterase, tetanus,
tuberculosis, burns, debilitating disease,
malignancy, chronic anaemia and
malnutrition, hepatic failure, renal failure,
autoimmune diseases such as myxoedema
and collagen diseases, following
plasma exchange, plasmapheresis,
cardiopulmonary bypass and as a result of
drug interactions.
If Suxamethonium Chloride is given over
a prolonged period, the characteristic
depolarising neuromuscular (or Phase
I) block may change to one with
characteristics of a non-depolarising (or
Phase II) block. Although the characteristics
of a developing Phase II block resemble
those of a true non-depolarising block,
the former cannot always be fully or
permanently reversed by anticholinesterase
agents. When a Phase II block is fully
established, its effects will then usually
be fully reversible with standard doses
of neostigmine accompanied by an
anticholinergic agent.

In healthy adults, suxamethonium
occasionally causes a mild transient slowing
of the heart rate on initial administration.
Bradycardias are more commonly observed
in children and on repeated administration
of suxamethonium in both children and
adults. Pre-treatment with intravenous
atropine or glycopyrrolate significantly
reduces the incidence and severity of
suxamethonium-related bradycardia.
In the absence of pre-existing or evoked
hyperkalaemia, ventricular arrhythmias
are rarely seen following suxamethonium
administration. Patients taking digitalis-like
drugs are however more susceptible to such
arrhythmias. The action of suxamethonium
on the heart may cause changes in cardiac
rhythm including cardiac arrest.
Suxamethonium must not be administered
to patients with advanced myasthenia
gravis as the patients may develop Phase 2
block which can result in delayed recovery.
Patients with myasthenic Eaton Lambert
syndrome are more sensitive than normal
to suxamethonium which demands a
reduction in dose.
Tachyphylaxis occurs after repeated
administration of suxamethonium.
Some authorities advocate routine
premedication of paediatric patients
with intravenous atropine. Intramuscular
atropine is not effective. Pretreatment with
intravenous atropine or glycopyrrolate
significantly reduces the incidence and
severity of suxamethonium-related
bradycardia. Extra care or monitoring must
be carried out on infants and children being
given suxamethonium, due to the increased
risks of undiagnosed muscular disorders
or unknown predisposition to malignant
Suxamethonium Chloride should not be
mixed in the same syringe with any other
agent, especially thiopental.
Suxamethonium Chloride is acidic and
should not be mixed with highly alkaline
solutions, e.g. barbiturates.
In patients with severe sepsis, the potential
for hyperkalaemia seems to be related to
the severity and duration of infection.
Interaction with other medicinal
products and other forms of interaction
Suxamethonium, a depolarising muscle
relaxant of short duration, may interact with
the following:
Anti-arrhythmics: Lidocaine, procaine,
procainamide, chloroprocaine, cocaine,
quinidine and verapamil enhance muscle
relaxant effect.
Antibacterials: effect of muscle relaxants
is enhanced by aminoglycosides such
as dibekacin, kanamycin, neomycin,
ribostamycin and streptomycin, the effect
of suxamethonium is also enhanced by
vancomycin, azlocillin, clindamycin, colistin,
piperacillin and polymyxin B.
Continued overleaf

Package leaflet: information for the user

Suxamethonium Chloride 50mg/ml
Solution for Injection
Suxamethonium Chloride
Read all of this leaflet carefully before you use Suxamethonium Chloride Injection.
• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor or pharmacist.
• If any of the side effects get serious, or if you notice any side effects not listed in this
leaflet, please tell your doctor or pharmacist.

In this leaflet:
1. What Suxamethonium Chloride Injection
is and what it is used for
2. Before having Suxamethonium Chloride
3. How Suxamethonium Chloride Injection
is given
4. Possible side effects
5. Storing Suxamethonium Chloride
6. Further information

1. What Suxamethonium
Chloride Injection is and what
it is used for
The active ingredient Suxamethonium
Chloride is a medicine that relaxes the
muscles of the body.
Suxamethonium Chloride Injection is used
to help your muscles relax during surgery
or medical procedures. It is also used to
reduce the strength of muscle contractions
associated with drug-induced convulsions
(fits) or with electro-convulsive therapy

2. Before having Suxamethonium
Chloride Injection
You should not be given Suxamethonium
Chloride Injection if:
• you are allergic to Suxamethonium
Chloride or any of the other ingredients
listed in section 6 of this leaflet
• you are pregnant, trying to become
pregnant or breast-feeding
• your doctor has told you that you suffer
from abnormal cholinesterase activity
• you or any of your family have a history of
abnormally high body temperature
• you are recovering from major trauma or
severe burns
• you have suffered a spinal cord injury,
nerve injury or sudden muscle wasting
• you have abnormally high levels of
potassium in your blood (hyperkalaemia)
• you have any eye injuries
• you have a disease causing weakness of
the muscles (myotonia congenita,
dystrophia myotonica or myasthenia
• you have muscle weakness and wasting
of muscle tissue (Duchenne muscular
dystrophy (DMD))
• you have not been able to walk for a
long period of time.
Take special care with Suxamethonium
Chloride Injection if:
• you are suffering from an infection that
causes muscle stiffness (tetanus)
• you are suffering from tuberculosis
• you feel unwell

• you have a fever
• you have severe burns
• you have cancer
• you suffer from a blood disease known as
• you suffer from a lack of proper nutrition
or an inability to absorb nutrients from
food (malnutrition)
• you have serious liver or kidney problems
• you suffer from a disease caused by the
body attacking itself (autoimmune
disease) such as a disease of the thyroid
gland (myxoedema)
• you suffer from diseases that cause
problems with the joints (collagen
• you suffer from heart problems (including
heart attacks, heart disease or an irregular
heart beat)
• you are having or have had in the past
treatment to your blood known as
plasmapheresis therapy
• you have a blood infection (sepsis)
• you have had any head injuries
Special care should be taken when this
medicine is being given to children and the
If any of the above apply to you or your
child, please consult your doctor.
Taking other medicines
Please tell your doctor or nurse if you are
taking or have recently taken any other
medicines, including those obtained
without prescription, including:
• anti-arrhythmics (drugs used to alter the
rhythm of the heart) e.g. lidocaine,
procaine and cocaine.
• antibacterials (drugs able to kill bacteria)
e.g. neomycin, vancomycin and
polymyxin B
• anticholinesterases (drugs used to treat
muscle problems) such as neostigmine
• ecothiopate, a medicine used to treat
raised pressure in the eye (glaucoma)
• metoclopramide, a medicine used to
stop you feeling or being sick
• phenelzine, a medicine used to treat
depression (monoamine oxidase
• promazine, a medicine used to treat
restlessness and agitation
• medicines used to treat malaria such as
quinine and chloroquine
• tacrine, a medicine used to treat
Alzheimers disease
• oestrogen and testosterone, medicines
used to treat hormone problems
• antiepileptics (drugs used to stop fits) e.g.
carbamazepine and phenytoin
• antihypertensives (drugs used to lower
blood pressure) e.g. trimetaphan
• antineoplastics (drugs used to treat cancer)
e.g. cyclophosphamide and tretamine
Continued overleaf

• benzodiazepines (drugs which help you to
relax) e.g. diazepam and midazolam
• beta-blockers (drugs which slow the
activity of the heart) e.g. propranolol
• calcium-channel blockers (drugs which
reduce the strength of the heart) e.g.
nifedipine, verapamil or dantrolene.
• cardiac glycosides (drugs which increase
heart muscle contraction) e.g. digoxin
• cytotoxics (a type of medicine used to
treat cancer) e.g. cyclophosphamide and
• general anaesthetics (drugs used to put
you to sleep for surgery) e.g. propofol,
fentanyl citrate-droperidol (Innovar) and
• histamine antagonists (drugs used to
treat allergies) e.g. cimetidine
• lithium (a drug used to control overexcitement and/or depression)
• magnesium salts (a dietary supplement)
• medicines that affect the nervous system
(parasympathomimetics and
sympathomimetics) e.g. demecarium,
neostigmine, donepezil, bambuterol.
Tell your doctor if you have recently been
exposed to pesticides e.g. sheep dip.
If you have any doubts about whether this
medicine should be administered to you,
consult your doctor or nurse.
Pregnancy & breast-feeding
You should not be given Suxamethonium
Chloride Injection if you are pregnant, trying
to become pregnant or breast-feeding. Ask
your doctor for advice before taking any
Effects on the ability to drive and use
Do not attempt to drive or operate

3. How Suxamethonium
Chloride Injection is given
Suxamethonium Chloride Injection will be
given to you as an injection into your vein
(intravenously) and/or into muscle
(intramuscularly). The dose depends on
your individual needs, body weight, the
amount of muscular relaxation required and
the route of administration of the drug.
Adults, the elderly and children over
12 years
By intravenous injection:
1mg per kilogram of bodyweight, usually
Supplementary doses of around 50% to
100% of the initial dose given at 5 to 10
minute intervals will maintain muscle
A maximum of 500mg/hour will be given.
By intravenous infusion (drip):
0.1-0.2% solution, 2.5 to 4mg per minute up
to a maximum of 500mg per hour
By intravenous injection:
(Children 1-12 1-2mg per kilogram of
years of age): bodyweight up to a
maximum of 150mg
2mg per kilogram of
(under 1 year): bodyweight up to a
maximum of 150mg

By intramuscular injection:
(Children 1-12 up to 4mg per kilogram of
years of age): bodyweight up to a
maximum of 150mg
up to 4-5mg per kilogram of
(under 1 year): bodyweight up to a
maximum of 150mg
If you are given too much
Suxamethonium Chloride Injection
As this medicine will be given to you whilst
you are in hospital, it is unlikely that you will
be given too little or too much, however,
tell your doctor or nurse if you have any

4. Possible side effects
Like all medicines, Suxamethonium Chloride
Injection can cause side effects, although not
everybody gets them.
Possible side effects include:
• muscle pain or stomach ache
• a very slow or fast heart beat or irregular
heart beats
• difficulty in breathing
• feeling very hot and facial flushing
• symptoms of an allergic reaction such as
a skin rash
• blurred vision or problems with your
• increased saliva or mucus production
If any of the side effects get serious, or if
you notice any side effects not listed in this
leaflet, please tell your doctor or nurse.

5. Storing Suxamethonium
Chloride Injection
Keep out of the reach and sight of children.
You should not be given Suxamethonium
Chloride Injection after the expiry date which
is printed on the carton and ampoule label.
The doctor or nurse will check that the expiry
date on the label has not been passed before
administering the injection to you. The expiry
date refers to the last day of that month.
Store at 2°C–8°C. Do not freeze. Keep
container in the outer box.

6. Further Information

Anticholinesterases: Cholinesterase
and pseudocholinesterase both
degrade suxamethonium. Therefore
anticholinesterases will enhance
suxamethonium. Examples of
anticholinesterases include aprotinin,
cyclophosphamide, dexpanthenol,
ecothiopate, metoclopramide (nonselective drug), neostigmine, phenelzine
(MAOI), promazine, quinine and chloroquine
(antimalarials), tacrine and trimetaphan
(ganglion blocking drug), oestrogen and
testosterone. Exposure to pesticides may
also reduce pseudocholinesterase activity
such as diazinon, malathion and sheep dips.

Antineoplastics (anticancer drugs):
cyclophosphamide, chlormethine,
thiotepa and tretamine all reduce
pseudocholinesterase activity.

Suxamethonium should not be
administered to a pregnant or lactating
Suxamethonium has no direct action
on the uterus or other smooth muscle
structures. In normal therapeutic doses
it does not cross the placental barrier in
sufficient amounts to affect the respiration
of the infant. The benefits of the use of
suxamethonium as part of a rapid sequence
induction for general anaesthesia normally
outweighs the possible risk to the foetus.
Plasma cholinesterase levels fall during
the first trimester of pregnancy to about
70 to 80% of their pre-pregnancy values; a
further fall to about 60 to 70% of the prepregnancy levels occurs within 2 to 4 days
after delivery. Plasma cholinesterase levels
then increase to reach normal over the next
6 weeks. Consequently, a high proportion
of pregnant and puerperal patients may
exhibit mildly prolonged neuromuscular
blockade following Suxamethonium
It is not known whether suxamethonium or
its metabolites are excreted in human milk.

Beta-blockers: propranolol enhances muscle
relaxant effect.

Effects on ability to drive and use

Benzodiazepines: diazepam and
midazolam may alter the depth/duration of

Do not attempt to drive or operate

Antiepileptics: effect of muscle relaxants
antagonised by carbamazepine and
phenytoin (recovery from neuromuscular
blockade accelerated).
Antihypertensives: trimetaphan can
increase the effects of suxamethonium.

Calcium-channel Blockers: nifedipine
and verapamil enhance effect of nondepolarising muscle relaxants; hypotension,
myocardial depression, and hyperkalaemia
reported with intravenous dantrolene and
Cardiac Glycosides: increased risk of
arrhythmias if suxamethonium is given with
Cytotoxics: cyclophosphamide and thiotepa
enhance effect of suxamethonium.

What Suxamethonium Chloride Injection
The active substance is suxamethonium
chloride 50mg/ml.
The other ingredients are hydrochloric acid,
water for injections and nitrogen.
What Suxamethonium Chloride Injection
looks like and contents of the pack
Suxamethonium Chloride injection is a clear,
colourless solution supplied in a clear glass
2ml ampoule. Each ampoule contains 100mg
of suxamethonium chloride.
Marketing Authorisation Holder and
Martindale Pharmaceuticals Ltd.,
Bampton Road, Harold Hill,
Romford, Essex. RM3 8UG UK

General Anaesthetics: propofol can
cause serious bradycardia if given with
suxamethonium and fentanyl citratedroperidol (Innovar) enhances the effects
of suxamethonium. Suxamethonium
also interacts with halothane, isoflurane,
enflurane, cyclopropane, propanidid and

If you would like any more information, or
would like the leaflet in a different format,
please contact Medical Information at the
above address

Parasympathomimetics: demecarium and
ecothiopate eye-drops, neostigmine and
pyridostigmine, and possibly donepezil
enhance effect of suxamethonium but
antagonise effect of non-depolarising
muscle relaxants.

Product license number: PL 00156/0110
Date of last revision: August 2012

Pregnancy and lactation

Histamine Antagonists: high
concentrations of cimetidine may inhibit
Lithium: lithium enhances muscle relaxant
Magnesium Salts: parenteral magnesium
enhances effect of suxamethonium.

Undesirable effects
Muscle pains are frequently experienced
after administration of suxamethonium
and most commonly occur in ambulatory
patients undergoing short surgical
procedures under general anaesthesia.
There appears to be no direct connection
between the degree of visible muscle
fasciculation after suxamethonium
administration and the incidence or
severity of pain. The use of small doses
of non-depolarising muscle relaxants
given minutes before suxamethonium
administration has been advocated for
the reduction of incidence and severity of
suxamethonium-associated muscle pains.
This technique may require the use of
doses of suxamethonium in excess of 1mg/
kg to achieve satisfactory conditions for
endotracheal intubation.
The following adverse reactions have
been reported after administration of
Cardiovascular: bradycardia, tachycardia,
hypertension, hypotension, arrhythmias;
Respiratory: bronchospasm, prolonged
respiratory depression and apnoea;
Musculoskeletal: muscle fasciculation, postoperative muscle pains, myoglobinaemia,
Other: anaphylactic reactions,
hyperthermia, increased intra-ocular
pressure, increased intragastric pressure,
rash, skin flushing, excessive salivation.

There are case reports of hyperkalaemiarelated cardiac arrests following the
administration of suxamethonium to
patients with congenital cerebral palsy,
tetanus, Duchenne muscular dystrophy, and
closed head injury.
Profound, prolonged muscle paralysis with
respiratory depression are manifestations
of a suxamethonium overdose. Ventilatory
support is required.
The decision to use neostigmine to reverse
a Phase II suxamethonium-induced block
depends on the judgement of the clinician
in the individual case. Valuable information
in regard to this decision will be gained
by monitoring neuromuscular function.
If neostigmine is used, its administration
should be accompanied by appropriate
doses of an anticholinergic agent such as
Pharmacodynamic properties
Suxamethonium is closely related in
structure to acetylcholine. Suxamethonium
is quickly hydrolysed by plasma
cholinesterase. Suxamethonium acts
on the skeletal muscle motor endplate
just like acetylcholine as an agonist, to
cause flaccid paralysis of muscle (phase
1 block). Suxamethonium diffuses slowly
to the endplate and the concentration
at the endplate persists for long enough
to cause loss of electrical excitability. The
depolarization of the muscle endplate
establishes a voltage gradient and this
causes opening of voltage-dependent ion
channels of the muscle leading to transient
contraction of the muscle. Although the
end-plate stays depolarised, the muscle
membrane accounts for this depolarization
and remains flaccid. If suxamethonium is
kept continuously present during infusion,
the junctional membrane slowly regains
its resting potential with the return of
neuromuscular transmission; to maintain
the effect, a higher infusion rate is required
(tachyphylaxis). With continued infusion,
neuromuscular transmission will fail again
(phase 2 block) even though the membrane
potential of the end-plate stays unchanged
and normal or near normal. A phase 2
block has clinical characteristics of a nondepolarizing block. A phase 2 block may be
associated with prolonged neuromuscular
blockade and apnoea. The mechanism
of this block is not known but channel
blocking by penetration of suxamethonium
into the sub-end plate cytoplasm,
intracellular accumulation of calcium and
sodium, the loss of intracellular potassium,
and activation of Na,K-ATPase all contribute.

Pharmacokinetic properties
Neuromuscular-blocking drugs are used
mainly in anaesthesia to produce muscle
relaxation. Although complete relaxation
can be produced by anaesthetic drugs
alone, the concentrations needed to
obliterate spinal reflexes are high and it is
much more satisfactory to produce paralysis
by blocking neuromuscular transmission.
The drugs are given intravenously,
and act within about 30 to 60 seconds.
Suxamethonium acts for about 2 to 6
minutes, being hydrolysed by plasma
cholinesterase (pseudocholinesterase). One
molecule of choline is split off rapidly to
form succinylmonocholine (a weak muscle
relaxant), which is then slowly hydrolysed
to succinic acid and choline. Only a small
proportion of suxamethonium is excreted
unchanged in the urine.
Preclinical safety data
There is no pre-clinical data of relevance to
the prescriber which is additional to that
already included in other sections of the
List of excipients
Hydrochloric Acid
Water for Injections
None Known
Shelf life
18 months
Special precautions for storage
Store at 2°C - 8°C. Do not freeze.
Keep container in the outer carton.
Nature and contents of container
Type I clear glass 2 ml ampoule
Special precaution for disposal and other
Use once and discard any remaining
Not for dilution.
Martindale Pharmaceuticals Ltd
Bampton Road
Harold Hill
Essex RM3 8UG
PL 00156/0110
August 2012

Sympathomimetics: bambuterol enhances
effect of suxamethonium.


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