SUCCINYL CHOLINE CHLORIDE
DESCRIPTION:
WARNING
RISK OF CARDIAC ARREST FROM HYPERKALEMIC
RHABDOMYOLYSIS
There have been rare reports of acute
rhabdomyolysis with hyperkalemia followed
by ventricular dysrhythmias, cardiac
arrest, and death after the administration
of succinylcholine to apparently healthy
children who were subsequently found to
have undiagnosed skeletal muscle myopathy,
most frequently Duchenne's muscular
dystrophy.
This syndrome often presents as peaked T-
waves and sudden cardiac arrest within
minutes after the administration of the
drug in healthy appearing children
(usually, but not exclusively, males, and
most frequently 8 years of age or younger).
There have also been reports in
adolescents.
Therefore, when a healthy appearing infant
or child develops cardiac arrest soon after
administration of succinylcholine, not felt
to be due to inadequate ventilation,
oxygenation or anesthetic overdose,
immediate treatment for hyperkalemia should
be instituted. This should include
administration of intravenous calcium,
bicarbonate, and glucose with insulin, with
hyperventilation. Due to the abrupt onset
of this syndrome, routine resuscitative
measures are likely to be unsuccessful.
However, extraordinary and prolonged
resuscitative efforts have resulted in
successful resuscitation in some reported
cases. In addition, in the presence of
signs of malignant hyperthermia,
appropriate treatment should be instituted
concurrently.
Since there may be no signs or symptoms to
alert the practitioner to which patients
are at risk, it is recommended that the
use of succinylcholine in children should
be reserved for emergency intubation or
instances where immediate securing of the
airway is necessary, e.g., laryngospasm,
difficult airway, full stomach, or for
intramuscular use when a suitable vein is
inaccessible (see PRECAUTIONS: Pediatric
Use and DOSAGE AND ADMINISTRATION).
THIS DRUG SHOULD BE USED ONLY BY INDIVIDUALS FAMILIAR WITH ITS ACTIONS,
CHARACTERISTICS, AND HAZARDS.
SCOLINE (succinylcholine chloride) is an ultra short-acting depolarizing-type,
skeletal muscle relaxant for intravenous administration.
Succinylcholine chloride is a white, odorless, slightly bitter powder and very
soluble in water. The drug is unstable in alkaline solutions but relatively
stable in acid solutions, depending upon the concentration of the solution and
the storage temperature. Solutions of succinylcholine chloride should be stored
under refrigeration to preserve potency. SCOLINE Injection is a sterile non-
pyrogenic solution for intravenous injection, containing 20 mg succinylcholine
chloride in eachmL and made isotonic with sodium chloride. The pH is adjusted to
3.5 with hydrochloric acid. Methylparaben (0.1%) is added as a preservative. The
chemical name for succinylcholine chloride is 2,2'-((1,4-dioxo- 1,4-
butanediyl)bis(oxy))bis(N,N,N- trimethylethanaminium) dichloride.
ACTIONS/CLINICAL PHARMACOLOGY:
Succinylcholine is a depolarizing skeletal muscle relaxant. As does
acetylcholine, it combines with the cholinergic receptors of the motor end plate
to produce depolarization. This depolarization may be observed as
fasciculations. Subsequent neuromuscular transmission is inhibited so long as
adequate concentration of succinylcholine remains at the receptor site. Onset of
flaccid paralysis is rapid (less than one minute after intravenous
administration), and with single administration lasts approximately 4 to 6
minutes.
Succinylcholine is rapidly hydrolyzed by plasma cholinesterase to
succinylmonocholine (which possesses clinically insignificant depolarizing
muscle relaxant properties) and then more slowly to succinic acid and choline
(see PRECAUTIONS). About 10% of the drug is excreted unchanged in the urine. The
paralysis following administration of succinylcholine is progressive, with
differing sensitivities of different muscles. This initially involves
consecutively the levator muscles of the face, muscles of the glottis and
finally the intercostals and the diaphragm and all other skeletal muscles.
Succinylcholine has no direct action on the uterus or other smooth muscle
structures. Because it is highly ionized and has low fat solubility, it does not
readily cross the placenta.
Tachyphylaxis occurs with repeated administration (see PRECAUTIONS).
Depending on the dose and duration of succinylcholine administration, the
characteristic depolarizing neuromuscular block (Phase I block) may change to a
block with characteristics superficially resembling a non- depolarizing block
(Phase II block). This may be associated with prolonged respiratory muscle
paralysis or weakness in patients who manifest the transition to Phase II block.
When this diagnosis is confirmed by peripheral nerve stimulation, it may
sometimes be reversed with anticholinesterase drugs such as neostigmine (see
PRECAUTIONS). Anticholinesterase drugs may not always be effective. If given
before succinylcholine is metabolized by cholinesterase, anticholinesterase
drugs may prolong rather than shorten paralysis.
Succinylcholine has no direct effect on the myocardium. Succinylcholine
stimulates both autonomic ganglia and muscarinic receptors which may cause
changes in cardiac rhythm, including cardiac arrest. Changes in rhythm,
including cardiac arrest, may also result from vagal stimulation, which may
occur during surgical procedures, or from hyperkalemia, particularly in children
(see PRECAUTIONS: Pediatric Use). These effects are enhanced by halogenated
anesthetics.
Succinylcholine causes an increase in intraocular pressure immediately after its
injection and during the fasciculation phase, and slight increases which may
persist after onset of complete paralysis (see WARNINGS). Succinylcholine may
cause slight increases in intracranial pressure immediately after its injection
and during the fasciculation phase (see PRECAUTIONS).
As with other neuromuscular blocking agents, the potential for releasing
histamine is present following succinylcholine administration. Signs and
symptoms of histamine mediated release such as flushing, hypotension and
bronchoconstriction are, however, uncommon in normal clinical usage.
Succinylcholine has no effect on consciousness, pain threshold or cerebration.
It should be used only with adequate anesthesia (see WARNINGS).
INDICATIONS AND USAGE:
Succinylcholine chloride is indicated as an adjunct to general anesthesia, to
facilitate tracheal intubation, and to provide skeletal muscle relaxation during
surgery or mechanical ventilation.
CONTRAINDICATIONS:
Succinylcholine is contraindicated in persons with personal or familial history
of malignant hyperthermia, skeletal muscle myopathies, and known
hypersensitivity to the drug. It is also contraindicated in patients after the
acute phase of injury following major burns, multiple trauma, extensive
denervation of skeletal muscle, or upper motor neuron injury, because
succinylcholine administered to such individuals may result in severe
hyperkalemia which may result in cardiac arrest (see WARNINGS). The risk of
hyperkalemia in these patients increases over time and usually peaks at 7 to 10
days after the injury. The risk is dependent on the extent and location of the
injury. The precise time of onset and the duration of the risk period are not
known.
WARNINGS:
WARNING
RISK OF CARDIAC ARREST FROM HYPERKALEMIC
RHABDOMYOLYSIS
There have been rare reports of acute
rhabdomyolysis with hyperkalemia followed
by ventricular dysrhythmias, cardiac
arrest, and death after the administration
of succinylcholine to apparently healthy
children who were subsequently found to
have undiagnosed skeletal muscle myopathy,
most frequently Duchenne's muscular
dystrophy.
This syndrome often presents as peaked T-
waves and sudden cardiac arrest within
minutes after the administration of the
drug in healthy appearing children
(usually, but not exclusively, males, and
most frequently 8 years of age or younger).
There have also been reports in
adolescents.
Therefore, when a healthy appearing infant
or child develops cardiac arrest soon after
administration of succinylcholine, not felt
to be due to inadequate ventilation,
oxygenation, or anesthetic overdose,
immediate treatment for hyperkalemia should
be instituted. This should include
administration of intravenous calcium,
bicarbonate, and glucose with insulin, with
hyperventilation. Due to the abrupt onset
of this syndrome, routine resuscitative
measures are likely to be unsuccessful.
However, extraordinary and prolonged
resuscitative efforts have resulted in
successful resuscitation in some reported
cases. In addition, in the presence of
signs of malignant hyperthermia,
appropriate treatment should be instituted
concurrently.
Since there may be no signs or symptoms to
alert the practitioner to which patients
are at risk, it is recommended that the
use of succinylcholine in children should
be reserved for emergency intubation or
instances where immediate securing of the
airway is necessary, e.g., laryngospasm,
difficult airway, full stomach, or for
intramuscular use when a suitable vein is
inaccessible (see PRECAUTIONS: Pediatric
Use and DOSAGE AND ADMINISTRATION).
THIS DRUG SHOULD BE USED ONLY BY
INDIVIDUALS FAMILIAR WITH ITS ACTIONS,
CHARACTERISTICS, AND HAZARDS.
SUCCINYLCHOLINE SHOULD BE USED ONLY BY THOSE SKILLED IN THE MANAGEMENT OF
ARTIFICIAL RESPIRATION AND ONLY WHEN FACILITIES ARE INSTANTLY AVAILABLE FOR
TRACHEAL INTUBATION AND FOR PROVIDING ADEQUATE VENTILATION OF THE PATIENT,
INCLUDING THE ADMINISTRATION OF OXYGEN UNDER POSITIVE PRESSURE AND THE
ELIMINATION OF CARBON DIOXIDE. THE CLINICIAN MUST BE PREPARED TO ASSIST OR
CONTROL RESPIRATION.
TO AVOID DISTRESS TO THE PATIENT, SUCCINYLCHOLINE SHOULD NOT BE ADMINISTERED
BEFORE UNCONSCIOUSNESS HAS BEEN INDUCED. IN EMERGENCY SITUATIONS, HOWEVER, IT
MAY BE NECESSARY TO ADMINISTER SUCCINYLCHOLINE BEFORE UNCONSCIOUSNESS IS
INDUCED.
SUCCINYLCHOLINE IS METABOLIZED BY PLASMA CHOLINESTERASE AND SHOULD BE USED WITH
CAUTION, IF AT ALL, IN PATIENTS KNOWN TO BE OR SUSPECTED OF BEING HOMOZYGOUS FOR
THE ATYPICAL PLASMA CHOLINESTERASE GENE.
HYPERKALEMIA: (SEE BOX WARNING)
Succinylcholine should be administered with GREAT CAUTION to patients suffering
from electrolyte abnormalities and those who may have massive digitalis
toxicity, because in these circumstances succinylcholine may induce serious
cardiac arrhythmias or cardiac arrest due to hyperkalemia.
GREAT CAUTION should be observed if succinylcholine is administered to patients
during the acute phase of injury following major burns, multiple trauma,
extensive denervation of skeletal muscle, or upper motor neuron injury (see
CONTRAINDICATIONS). The risk of hyperkalemia in these patients increases over
time and usually peaks at 7 to 10 days after the injury. The risk is dependent
on the extent and location of the injury. The precise time of onset and the
duration of the risk period are undetermined. Patients with chronic abdominal
infection, subarachnoid hemorrhage, or conditions causing degeneration of
central and peripheral nervous systems should receive succinylcholine with GREAT
CAUTION because of the potential for developing severe hyperkalemia.
MALIGNANT HYPERTHERMIA: Succinylcholine administration has been associated with
acute onset of malignant hyperthermia, a potentially fatal hypermetabolic state
of skeletal muscle. The risk of developing malignant hyperthermia following
succinylcholine administration increases with the concomitant administration of
volatile anesthetics. Malignant hyperthermia frequently presents as intractable
spasm of the jaw muscles (masseter spasm) which may progress to generalized
rigidity, increased oxygen demand, tachycardia, tachypnea and profound
hyperpyrexia. Successful outcome depends on recognition of early signs, such as
jaw muscle spasm, acidosis, or generalized rigidity to initial administration of
succinylcholine for tracheal intubation, or failure of tachycardia to respond to
deepening anesthesia. Skin mottling, rising temperature and coagulopathies may
occur later in the course of the hypermetabolic process. Recognition of the
syndrome is a signal for discontinuance of anesthesia, attention to increased
oxygen consumption, correction of acidosis, support of circulation, assurance of
adequate urinary output and institution of measures to control rising
temperature. Intravenous dantrolene sodium is recommended as an adjunct to
supportive measures in the management of this problem. Consult literature
references and the dantrolene prescribing information for additional information
about the management of malignant hyperthermic crisis. Continuous monitoring of
temperature and expired CO2 is recommended as an aid to early recognition of
malignant hyperthermia.
OTHER: In both adults and children the incidence of bradycardia, which may
progress to asystole, is higher following a second dose of succinylcholine. The
incidence and severity of bradycardia is higher in children than adults.
Pretreatment with anticholinergic agents (e.g., atropine) may reduce the
occurrence of bradyarrhythmias.
Succinylcholine causes an increase in intraocular pressure. It should not be
used in instances in which an increase in intraocular pressure is undesirable
(e.g., narrow angle glaucoma, penetrating eye injury) unless the potential
benefit of its use outweighs the potential risk.
Succinylcholine is acidic (pH = 3.5) and should not be mixed with alkaline
solutions having a pH greater than 8.5 (e.g., barbiturate solutions).
PRECAUTIONS:
(SEE BOX WARNING)
GENERAL: When succinylcholine is given over a prolonged period of time, the
characteristic depolarization block of the myoneural junction (Phase I block)
may change to a block with characteristics superficially resembling a non-
depolarizing block (Phase II block). Prolonged respiratory muscle paralysis or
weakness may be observed in patients manifesting this transition to Phase II
block. The transition from Phase I to Phase II block has been reported in 7 of 7
patients studied under halothane anesthesia after an accumulated dose of 2 to 4
mg/kg succinylcholine (administered in repeated, divided doses). The onset of
Phase II block coincided with the onset of tachyphylaxis and prolongation of
spontaneous recovery. In another study, using balanced anesthesia
(N2O/O2/narcotic-thiopental) and succinylcholine infusion, the transition was
less abrupt, with great individual variability in the dose of succinylcholine
required to produce Phase II block. Of 32 patients studied, 24 developed Phase
II block. Tachyphylaxis was not associated with the transition to Phase II
block, and 50% of the patients who developed Phase II block experienced
prolonged recovery.
When Phase II block is suspected in cases of prolonged neuromuscular blockade,
positive diagnosis should be made by peripheral nerve stimulation, prior to
administration of any anticholinesterase drug. Reversal of Phase II block is a
medical decision which must be made upon the basis of the individual, clinical
pharmacology and the experience and judgment of the physician. The presence of
Phase II block is indicated by fade of responses to successive stimuli
(preferably "train of four"). The use of an anticholinesterase drug to reverse
Phase II block should be accompanied by appropriate doses of an anticholinergic
drug to prevent disturbances of cardiac rhythm. After adequate reversal of Phase
II block with an anticholinesterase agent, the patient should be continually
observed for at least 1 hour for signs of return of muscle relaxation. Reversal
should not be attempted unless: (1) a peripheral nerve stimulator is used to
determine the presence of Phase II block (since anticholinesterase agents will
potentiate succinylcholine-induced Phase I block), and (2) spontaneous recovery
of muscle twitch has been observed for at least 20 minutes and has reached a
plateau with further recovery proceeding slowly; this delay is to ensure
complete hydrolysis of succinylcholine by plasma cholinesterase prior to
administration of the anticholinesterase agent. Should the type of block be
misdiagnosed, depolarization of the type initially induced by succinylcholine
(i.e., Phase I block) will be prolonged by an anticholinesterase agent.
Succinylcholine should be employed with caution in patients with fractures or
muscle spasm because the initial muscle fasciculations may cause additional
trauma.
Succinylcholine may cause a transient increase in intracranial pressure;
however, adequate anesthetic induction prior to administration of
succinylcholine will minimize this effect.
Succinylcholine may increase intragastric pressure, which could result in
regurgitation and possible aspiration of stomach contents.
Neuromuscular blockade may be prolonged in patients with hypokalemia or
hypocalcemia.
REDUCED PLASMA CHOLINESTERASE ACTIVITY: Succinylcholine should be used carefully
in patients with reduced plasma cholinesterase (pseudocholinesterase) activity.
The likelihood of prolonged neuromuscular block following administration of
succinylcholine must be considered in such patients (see DOSAGE AND
ADMINISTRATION).
Plasma cholinesterase activity may be diminished in the presence of genetic
abnormalities of plasma cholinesterase (e.g., patients heterozygous or
homozygous for atypical plasma cholinesterase gene), pregnancy, severe liver or
kidney disease, malignant tumors, infections, burns, anemia, decompensated heart
disease, peptic ulcer, or myxedema. Plasma cholinesterase activity may also be
diminished by chronic administration of oral contraceptives, glucocorticoids, or
certain monoamine oxidase inhibitors and by irreversible inhibitors of plasma
cholinesterase (e.g., organophosphate insecticides, echothiophate, and certain
antineoplastic drugs).
Patients homozygous for atypical plasma cholinesterase gene (1 in 2500 patients)
are extremely sensitive to the neuromuscular blocking effect of succinylcholine.
In these patients, a 5 to 10 mg test dose of succinylcholine may be administered
to evaluate sensitivity to succinylcholine, or neuromuscular blockade may be
produced by the cautious administration of a 1 mg/mL solution of succinylcholine
by slow intravenous infusion. Apnea or prolonged muscle paralysis should be
treated with controlled respiration.
DRUG INTERACTIONS: Drugs which may enhance the neuromuscular blocking action of
succinylcholine include: promazine, oxytocin, aprotinin, certain non-penicillin
antibiotics, quinidine, beta- adrenergic blockers, procainamide, lidocaine,
trimethaphan, lithium carbonate, magnesium salts, quinine, chloroquine,
diethylether, isoflurane, desflurane, metoclopramide and terbutaline. The
neuromuscular blocking effect of succinylcholine may be enhanced by drugs that
reduce plasma cholinesterase activity (e.g., chronically administered oral
contraceptives, glucocorticoids, or certain monoamine oxidase inhibitors) or by
drugs that irreversibly inhibit plasma cholinesterase (see PRECAUTIONS).
If other neuromuscular blocking agents are to be used during the same procedure,
the possibility of a synergistic or antagonistic effect should be considered.
CARCINOGENESIS, MUTAGENESIS, IMPAIRMENT OF FERTILITY: There have been no long-
term studies performed in animals to evaluate carcinogenic potential.
PREGNANCY: TERATOGENIC EFFECTS: Pregnancy Category C.
Animal reproduction studies have not been conducted with succinylcholine
chloride. It is also not known whether succinylcholine can cause fetal harm when
administered to a pregnant woman or can affect reproduction capacity.
Succinylcholine should be given to a pregnant woman only if clearly needed.
NONTERATOGENIC EFFECTS: Plasma cholinesterase levels are decreased by
approximately 24% during pregnancy and for several days postpartum. Therefore, a
higher proportion of patients may be expected to show increased sensitivity
(prolonged apnea) to succinylcholine when pregnant than when nonpregnant.
LABOR AND DELIVERY: Succinylcholine is commonly used to provide muscle
relaxation during delivery by caesarean section. While small amounts of
succinylcholine are known to cross the placental barrier, under normal
conditions the quantity of drug that enters fetal circulation after a single
dose of 1 mg/kg to the mother should not endanger the fetus. However, since the
amount of drug that crosses the placental barrier is dependent on the
concentration gradient between the maternal and fetal circulations, residual
neuromuscular blockade (apnea and flaccidity) may occur in the newborn after
repeated high doses to, or in the presence of atypical plasma cholinesterase in,
the mother.
NURSING MOTHERS: It is not known whether succinylcholine is excreted in human
milk. Because many drugs are excreted in human milk, caution should be exercised
following succinylcholine administration to a nursing woman.
PEDIATRIC USE: There are rare reports of ventricular dysrhythmias and cardiac
arrest secondary to acute rhabdomyolysis with hyperkalemia in apparently healthy
children who receive succinylcholine (see BOX WARNING). Many of these children
were subsequently found to have a skeletal muscle myopathy such as Duchenne's
muscular dystrophy whose clinical signs were not obvious. The syndrome often
presents as sudden cardiac arrest within minutes after the administration of
succinylcholine. These children are usually, but not exclusively, males, and
most frequently 8 years of age or younger. There have also been reports in
adolescents. There may be no signs or symptoms to alert the practitioner to
which patients are at risk. A careful history and physical may identify
developmental delays suggestive of a myopathy. A preoperative creatine kinase
could identify some but not all patients at risk. Due to the abrupt onset of
this syndrome, routine resuscitative measures are likely to be unsuccessful.
Careful monitoring of the electrocardiogram may alert the practitioner to peaked
T-waves (an early sign). Administration of intravenous calcium, bicarbonate, and
glucose with insulin, with hyperventilation have resulted in successful
resuscitation in some of the reported cases. Extraordinary and prolonged
resuscitative efforts have been effective in some cases. In addition, in the
presence of signs of malignant hyperthermia, appropriate treatment should be
initiated concurrently (see WARNINGS). Since it is difficult to identify which
patients are at risk, it is recommended that the use of succinylcholine in
children should be reserved for emergency intubation or instances where
immediate securing of the airway is necessary, e.g., laryngospasm, difficult
airway, full stomach, or for intramuscular use when a suitable vein is
inaccessible.
As in adults, the incidence of bradycardia in children is higher following the
second dose of succinylcholine. The incidence and severity of bradycardia is
higher in children than adults. Pre-treatment with anticholinergic agents, e.g.,
atropine, may reduce the occurrence of bradyarrhythmias.
DRUG INTERACTIONS:
Drugs which may enhance the neuromuscular blocking action of succinylcholine
include: promazine, oxytocin, aprotinin, certain non- penicillin antibiotics,
quinidine, beta- adrenergic blockers, procainamide, lidocaine, trimethaphan,
lithium carbonate, magnesium salts, quinine, chloroquine, diethylether,
isoflurane, desflurane, metoclopramide and terbutaline. The neuromuscular
blocking effect of succinylcholine may be enhanced by drugs that reduce plasma
cholinesterase activity (e.g., chronically administered oral contraceptives,
glucocorticoids, or certain monoamine oxidase inhibitors) or by drugs that
irreversibly inhibit plasma cholinesterase (see PRECAUTIONS).
If other neuromuscular blocking agents are to be used during the same procedure,
the possibility of a synergistic or antagonistic effect should be considered.
(See Also PRECAUTIONS)
ADVERSE REACTIONS:
Adverse reactions to succinylcholine consist primarily of an extension of its
pharmacological actions. Succinylcholine causes profound muscle relaxation
resulting in respiratory depression to the point of apnea; this effect may be
prolonged. Hypersensitivity reactions, including anaphylaxis, may occur in rare
instances. The following additional adverse reactions have been reported:
cardiac arrest, malignant hyperthermia, arrhythmias, bradycardia, tachycardia,
hypertension, hypotension, hyperkalemia, prolonged respiratory depression or
apnea, increased intraocular pressure, muscle fasciculation, jaw rigidity,
postoperative muscle pain, rhabdomyolysis with possible myoglobinuric acute
renal failure, excessive salivation, and rash.
OVERDOSAGE:
Overdosage with succinylcholine may result in neuromuscular block beyond the
time needed for surgery and anesthesia. This may be manifested by skeletal
muscle weakness, decreased respiratory reserve, low tidal volume, or apnea. The
primary treatment is maintenance of a patent airway and respiratory support
until recovery of normal respiration is assured. Depending on the dose and
duration of succinylcholine administration, the characteristic depolarizing
neuromuscular block (Phase I) may change to a block with characteristics
superficially resembling a non- depolarizing block (Phase II) (see PRECAUTIONS).
DOSAGE AND ADMINISTRATION:
The dosage of succinylcholine should be individualized and should always be
determined by the clinician after careful assessment of the patient (see
WARNINGS).
Parenteral drug products should be inspected visually for particulate matter and
discoloration prior to administration whenever solution and container permit.
Solutions which are not clear and colorless should not be used.
ADULTS:
FOR SHORT SURGICAL PROCEDURES: The average dose required to produce
neuromuscular blockade and to facilitate tracheal intubation is 0.6 mg/kg
SCOLINE (succinylcholine chloride) Injection given intravenously. The optimum
dose will vary among individuals and may be from 0.3 to 1.1 mg/kg for adults.
Following administration of doses in this range, neuromuscular blockade develops
in about 1 minute; maximum blockade may persist for about 2 minutes, after which
recovery takes place within 4 to 6 minutes. However, very large doses may result
in more prolonged blockade. A 5 to 10 mg test dose may be used to determine the
sensitivity of the patient and the individual recovery time (see PRECAUTIONS).
FOR LONG SURGICAL PROCEDURES: The dose of succinylcholine administered by
infusion depends upon the duration of the surgical procedure and the need for
muscle relaxation. The average rate for an adult ranges between 2.5 and 4.3 mg
per minute.
Solutions containing from 1 to 2 mg per mL succinylcholine have commonly been
used for continuous infusion. The more dilute solution (1 mg per mL) is probably
preferable from the standpoint of ease of control of the rate of administration
of the drug and, hence, of relaxation. This intravenous solution containing 1 mg
per mL may be administered at a rate of 0.5 mg (0.5 mL) to 10 mg (10 mL) per
minute to obtain the required amount of relaxation. The amount required per
minute will depend upon the individual response as well as the degree of
relaxation required. Avoid overburdening the circulation with a large volume of
fluid. It is recommended that neuromuscular function be carefully monitored with
a peripheral nerve stimulator when using succinylcholine by infusion in order to
avoid overdose, detect development of Phase II block, follow its rate of
recovery, and assess the effects of reversing agents (see PRECAUTIONS).
Intermittent intravenous injections of succinylcholine may also be used to
provide muscle relaxation for long procedures. An intravenous injection of 0.3
to 1.1 mg/kg may be given initially, followed, at appropriate intervals, by
further injections of 0.04 to 0.07 mg/kg to maintain the degree of relaxation
required.
PEDIATRICS: For emergency tracheal intubation or in instances where immediate
securing of the airway is necessary, the intravenous dose of succinylcholine is
2 mg/kg for infants and small children; for older children and adolescents the
dose is 1 mg/kg (see BOX WARNING and PRECAUTIONS: Pediatric Use.)
Rarely, IV bolus administration of succinylcholine in infants and children may
result in malignant ventricular arrhythmias and cardiac arrest secondary to
acute rhabdomyolysis with hyperkalemia. In such situations, an underlying
myopathy should be suspected.
Intravenous bolus administration of succinylcholine in infants or children may
result in profound bradycardia or, rarely, asystole. As in adults, the incidence
of bradycardia in children is higher following a second dose of succinylcholine.
The occurrence of bradyarrhythmias may be reduced by pretreatment with atropine
(see PRECAUTIONS: Pediatric Use).
INTRAMUSCULAR USE: If necessary, succinylcholine may be given intramuscularly
to infants, older children or adults when a suitable vein is inaccessible. A
dose of up to 3 to 4 mg/kg may be given, but not more than 150 mg total dose
should be administered by this route. The onset of effect of succinylcholine
given intramuscularly is usually observed in about 2 to 3 minutes.
COMPATIBILITY AND ADMIXTURES: Succinylcholine is acidic (pH 3.5) and should not
be mixed with alkaline solutions having a pH greater than 8.5 (e.g., barbiturate
solutions). Admixtures containing 1 to 2 mg/mL may be prepared by adding 1 g
succinylcholine to 1000 or 500 mL sterile solution, such as 5% Dextrose
Injection USP or 0.9% Sodium Chloride Injection USP. Admixtures of SCOLINE must
be used within 24 hours after preparation. Aseptic techniques should be used to
prepare the diluted product. Admixtures of SCOLINE should be prepared for
single patient use only. The unused portion of diluted SCOLINE should be
discarded.
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