Risk of acute rhabdomyolysis with hyperkalemia followed by ventricular arrhythmias, cardiac arrest, and death in apparently healthy children and adolescents who subsequently were found to have undiagnosed skeletal muscle myopathy (e.g., Duchenne’s muscular dystrophy).
Use in children and adolescents should be reserved for those undergoing emergency intubation, those in whom an airway should be secured immediately (e.g., those with laryngospasm, difficult airway, or full stomach), or those in whom a suitable vein is not accessible and IM administration is needed. (See Pediatric Use under Cautions.)
Experience of Clinician
Should be administered only by individuals experienced in the use of neuromuscular blocking agents.
Drug of choice for skeletal muscle relaxation during orthopedic manipulations. (See Orthopedic Precautions under Cautions.)
Facilitation of endotracheal intubation; generally preferred in emergency situations where rapid intubation is required.
Treatment to increase pulmonary compliance during assisted or controlled respiration.
Dosage and Administration
General
Carefully adjust dosage according to individual requirements and response.
To avoid patient distress, generally administer only after unconsciousness has been induced; however, may administer before unconsciousness has been induced in emergency situations.
To evaluate patient’s ability to metabolize succinylcholine and to determine individual patient sensitivity and recovery time, a test dose may be administered to spontaneously breathing patient after anesthesia has been induced. (See Test Dose under Dosage and Administration.)
Assess neuromuscular blockade and recovery in patients undergoing anesthesia; careful assessment with a peripheral nerve stimulator is recommended during continuous IV infusions to monitor the degree of neuromuscular blockade, to detect the development of phase II block, and to minimize the possibility of overdosage.
Administration
Administer IV or IM. IV administration is preferred; if necessary, administer IM in infants or other patients in whom a suitable vein is not accessible.
For specific procedures and techniques of administration, consult specialized references.
IV Administration
For solution and drug compatibility information, see Compatibility under Stability.
For prolonged procedures, administer by continuous IV infusion (preferably) or intermittent IV injection.
Multiple fractional doses generally should not be used; repeated fractional doses and, to a lesser extent, continuous infusion, may lead to tachyphylaxis. (See Prolonged or Repeated Administration under Cautions.)
Dilution
For continuous IV infusion, dilute succinylcholine chloride to a concentration of 1–2 mg/mL in 5% dextrose injection, 5% dextrose and 0.9% sodium chloride injection, 0.9% sodium chloride injection, or (1/6) M sodium lactate injection. 1 mg/mL usually is used for optimum dosage control; 2 mg/mL may be preferred if amount of fluid should be limited.
Do not admix with alkaline solutions. (See Compatibility under Stability.)
Rate of Administration
Administer dose over 10–30 seconds for short procedures.
Individualize rate of continuous IV infusion.
IM Administration
Administer by deep IM injection, preferably high into deltoid muscle.
Dosage
Available as succinylcholine chloride; dosage expressed in terms of the salt.
Pediatric Patients
Skeletal Muscle Relaxation
IV
Infants and small children: 2 mg/kg.
Older children and adolescents: 1 mg/kg.
If necessary, administer additional doses in accordance with patient’s response.
Continuous IV infusions considered unsafe in neonates and children. (See Pediatric Use under Cautions.)
IM
Infants and older children: up to 3–4 mg/kg (maximum 150 mg).
Adults
Skeletal Muscle Relaxation
Test Dose
IV
0.1 mg/kg (approximately 5–10 mg). If test dose produces moderate muscle relaxation, 20-mg dose probably sufficient for short procedures; if test dose produces minimum relaxation, 30 mg probably needed.
Dosage for Procedure
IV
For short procedures, usual dose is 0.6 mg/kg (range 0.3–1.1 mg/kg); if necessary, administer additional doses in accordance with patient’s response. (See Onset and also Duration under Pharmacokinetics.)
For prolonged procedures, usual dosage is 2.5 mg/minute by continuous IV infusion; adjust rate (range: 0.5–10 mg/minute) depending on patient’s response and requirements. Alternatively, administer by intermittent IV injection: initially 0.3–1.1 mg/kg, followed by additional doses of 0.04–0.07 mg/kg as necessary to maintain adequate muscle relaxation. (see IV Administration under Dosage and Administration.) (See Onset and also Duration under Pharmacokinetics.)
IM
Up to 3–4 mg/kg (maximum 150 mg). (See Onset and also Duration under Pharmacokinetics.)
Prescribing Limits
Pediatric Patients
Skeletal Muscle Relaxation
IM
Maximum total dose 150 mg.
Adults
Skeletal Muscle Relaxation
IM
Maximum total dose 150 mg.
Special Populations
Geriatric Patients
Careful dosage selection recommended due to possible age-related decrease in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy; initiate therapy at low end of dosage range.
Patients with Reduced Plasma Cholinesterase Activity
Administer small test dose (5–10 mg) or cautiously administer 1-mg/mL solution by slow IV infusion. (See Patients Homozygous for the Atypical Plasma Cholinesterase Gene and also Reduced Plasma Cholinesterase Activity, under Cautions.)
Myopathies associated with elevated serum creatine kinase (CK, CPK) values.
Upper motor neuron injury, multiple trauma, extensive or severe burns, extensive denervation of skeletal muscle because of CNS disease or injury. (See Hyperkalemia under Cautions.)
Known hypersensitivity to succinylcholine or any ingredient in the formulation.
Warnings/Precautions
Warnings
Respiratory Effects
Potential for severely compromised respiratory function and respiratory paralysis. Complete or prolonged respiratory paralysis frequently occurs at doses >1 mg/kg.
Possible transient apnea with single doses ≤30 mg or infusion rates of 2.5 mg/minute; however, spontaneous respiration usually returns in a few seconds or a maximum of 4 minutes. Institute oxygen if spontaneous respiration does not occur promptly. Avoid hyperventilation (may prolong apnea).
Should be used only by individuals experienced in the use of neuromuscular blocking agents and in the maintenance of an adequate airway and respiratory support. Facilities and personnel necessary for intubation, administration of oxygen, and assisted or controlled respiration should be immediately available.
Use with caution in patients with pulmonary impairment or respiratory depression.
Patients Homozygous for the Atypical Plasma Cholinesterase Gene
Possible prolonged respiratory depression and muscle relaxation in patients homozygous for the atypical plasma cholinesterase gene. Use with extreme caution, if at all, in such patients. (See Patients with Reduced Plasma Cholinesterase Activity under Dosage and Administration.)
Hyperkalemia
Potential for acute rhabdomyolysis with hyperkalemia. (See Boxed Warning and also Pediatric Use under Cautions.)
Possible severe hyperkalemia resulting in serious cardiac arrhythmias or cardiac arrest in patients with upper motor neuron injury, multiple trauma, extensive or severe burns, or extensive denervation of skeletal muscle because of CNS disease or injury; use is contraindicated in these patients. Risk of hyperkalemia depends on extent and location of the injury, increases over time, usually peaks 7–10 days after the injury, and can persist for >6 months after neural injury.
Use with extreme caution in patients with preexisting hyperkalemia or those at increased risk of hyperkalemia (e.g., those with paraplegia, chronic abdominal infection, tetanus, subarachnoid hemorrhage, degenerative or dystrophic neuromuscular disease, or conditions that may cause degeneration of central and peripheral nervous systems).
Use with extreme caution in patients receiving quinidine or cardiac glycosides or those with suspected cardiac glycoside toxicity (due to potential for hyperkalemia).
Malignant Hyperthermia
Possible fatal malignant hyperthermia; manifested by a rapid, profound elevation in body temperature and sometimes extreme muscular rigidity. Risk increases with concomitant administration of inhalation anesthetics. (See Specific Drugs under Interactions.)
If malignant hyperthermia occurs, discontinue all anesthetic agents and initiate IV dantrolene therapy in conjunction with supportive measures (e.g., administering oxygen, treating metabolic acidosis, instituting cooling procedures); maintain urinary output and monitor serum electrolytes.
Bradycardia
Possible profound bradycardia resulting from vagal stimulation and accompanied by hypotension and cardiac arrhythmias (e.g., nodal rhythms, extrasystoles, bigeminy, AV block, cardiac arrest).
Occurs most commonly with repeated administration and in children (see Pediatric Use under Cautions).
Prior administration of atropine may inhibit vagal stimulation and reduce occurrence of bradycardia.
Use with extreme caution in patients with electrolyte disturbances, those receiving quinidine or cardiac glycosides, or those with suspected cardiac glycoside toxicity.
Ophthalmic Effects
Possible increased intraocular pressure.
Use not recommended in patients with angle-closure glaucoma or penetrating eye injuries. Use with extreme caution, if at all, during ocular surgery; nondepolarizing neuromuscular blocking agent may be preferred.
Sensitivity Reactions
Hypersensitivity Reactions
Hypersensitivity reactions, including anaphylaxis, reported rarely.
General Precautions
Prolonged or Repeated Administration
Possible tachyphylaxis and prolonged and difficult-to-reverse apnea; multiple fractional doses alone generally should not be used.
Possible prolonged neuromuscular blockade due to change of the characteristic depolarizing neuromuscular block (phase I block) to a phase II block.
To reverse phase II block, administer a cholinesterase inhibitor (e.g., neostigmine, pyridostigmine, edrophonium), in conjunction with an antimuscarinic (e.g., atropine, glycopyrrolate) to prevent disturbances in cardiac rhythm. Use a peripheral nerve stimulator to confirm change to phase II block prior to administering cholinesterase inhibitor.
To ensure complete hydrolysis of succinylcholine by plasma pseudocholinesterase prior to administration of cholinesterase inhibitor, do not attempt reversal unless spontaneous recovery of muscle twitch has been observed for ≥20 minutes and has plateaued, with further recovery from neuromuscular blockade occurring slowly. (See Actions.)
Possible increased intragastric pressure secondary to fasciculation of abdominal muscles; potential for regurgitation and possible aspiration of stomach contents. May be prevented by prior administration of small dose of nondepolarizing neuromuscular blocking agent.
Reduced Plasma Cholinesterase Activity
Possible prolonged respiratory depression and muscle relaxation in patients with reduced plasma cholinesterase activity.
Plasma cholinesterase activity may be reduced in patients heterozygous for the atypical pseudocholinesterase gene, pregnant women, and patients with severe hepatic or renal disease, malnutrition, infections, severe anemia, severe dehydration, burns, cancer, collagen diseases, myxedema, decompensated heart disease, peptic ulcer disease, or abnormal body temperature. (See Patients Homozygous for the Atypical Plasma Cholinesterase Gene under Cautions and also see Specific Drugs under Interactions.)
Some clinicians recommend determining plasma pseudocholinesterase activity prior to administration.
Administer with extreme caution and in reduced doses, if at all, in patients with abnormally low pseudocholinesterase concentrations. If low concentrations are suspected, a test dose or cautious continuous IV infusion may be administered. (See Test Dose and also Patients with Reduced Plasma Cholinesterase Activity, under Dosage and Administration.)
Treat apnea or prolonged muscle paralysis with controlled respiration. Administration of fresh whole blood or plasma may restore pseudocholinesterase concentrations.
Electrolyte Disturbances
Possible prolonged neuromuscular blockade in patients with electrolyte disturbances (e.g., hypocalcemia, hypokalemia). Use with caution. (See Hyperkalemia and also Bradycardia under Cautions.)
Histamine Release
Possible histamine release; manifestations associated with histamine release (e.g., flushing, erythema, pruritus, urticaria, wheal formation, wheezing, bronchospasm, hypotension) uncommon at usual dosages.
Orthopedic Precautions
Use with caution in patients with fractures, dislocations, or muscular spasms; initial muscle fasciculation may cause additional trauma.
Specific Populations
Pregnancy
Category C. (See Reduced Plasma Cholinesterase Activity under Cautions.)
Lactation
Not known whether succinylcholine is distributed into milk. Caution advised if succinylcholine is used.
Pediatric Use
Possible acute rhabdomyolysis with hyperkalemia followed by ventricular arrhythmias, cardiac arrest, and death; usually occurs in males ≤8 years of age. If cardiac arrest occurs, initiate treatment for hyperkalemia. Prolonged or extraordinary resuscitative measures may be required. Use in children and adolescents should be reserved for those undergoing emergency intubation, those in whom an airway should be secured immediately (e.g., those with laryngospasm, difficult airway, or full stomach), or those in whom a suitable vein is not accessible and IM administration is needed.
Possible profound bradycardia or, rarely, asystole when administered by rapid IV injection. Risk increases with repeated doses; consider pretreatment with atropine.
Possible risk of malignant hyperthermia; institute appropriate therapy if malignant hyperthermia occurs. Rarely, myoglobinuria and myoglobinemia have been reported in conjunction with malignant hyperthermia and muscle rigidity. Continuous IV infusions are considered unsafe in neonates and children due to risk of malignant hyperthermia. (See Malignant Hyperthermia under Cautions.)
Large amounts of benzyl alcohol (i.e., 100–400 mg/kg daily) have been associated with toxicity in neonates; some succinylcholine chloride injections may contain benzyl alcohol 10 mg/mL.
Geriatric Use
Use with caution due to greater frequency of decreased hepatic, renal, and/or cardiac function and of concomitant disease and drug therapy observed in the elderly. Titrate dosage carefully.
Hepatic Impairment
Possible decreased plasma cholinesterase activity in patients with severe hepatic impairment; use with caution. (See Elimination: Special Populations, under Pharmacokinetics.)
Renal Impairment
Possible decreased plasma cholinesterase activity in patients with severe renal impairment. Possible accumulation of succinylmonocholine, resulting in prolonged apnea. Use with caution.
Possible decreased plasma cholinesterase activity and increased neuromuscular blockade
Use with caution
Pharmacokinetics
Absorption
Bioavailability
Poorly absorbed from the GI tract.
Onset
Following IV administration, onset is rapid; complete muscle relaxation occurs within 0.5–1 minute following 10- to 30-mg dose.
Following IM administration, onset occurs in about 2–3 minutes.
Duration
Following IV administration, duration of action is short (about 2–3 minutes following 10- to 30-mg dose; effects gradually dissipate within 10 minutes). Duration of action may be prolonged when administered as continuous IV infusion or in fractional doses.
Following IM administration, duration of action ranges from 10–30 minutes.
Special Populations
Duration of action is prolonged in patients with low plasma pseudocholinesterase concentrations.
Distribution
Extent
Crosses the placenta in small amounts.
Elimination
Metabolism
Rapidly hydrolyzed by plasma pseudocholinesterase to succinylmonocholine and then more slowly to succinic acid and choline.
Elimination Route
Excreted in urine as active and inactive metabolites and small amounts of unchanged drug.
Special Populations
Severe hepatic impairment may decrease plasma pseudocholinesterase activity, resulting in increased duration of action due to reduced metabolism.
In patients with renal impairment, possible decreased plasma pseudocholinesterase activity and possible accumulation of succinylmonocholine.
Stability
Storage
Parenteral
Injection
2–8°C. Multiple-dose vials stable up to 14 days at room temperature.
Compatibility
For information on systemic interactions resulting from concomitant use, see Interactions.
Parenteral
May be incompatible with alkaline solutions with pH >8.5 (e.g., barbiturate solutions).
Produces skeletal muscle relaxation by causing a decreased response to acetylcholine (ACh) at the myoneural (neuromuscular) junction of skeletal muscle.
Exhibits high affinity for ACh receptor sites and produces depolarization of motor end-plate at myoneural junction, resulting in transient twitching or fasciculation of skeletal muscles, followed by muscle paralysis (phase I block).
Prolonged or repeated administration results in gradual and variable transition to phase II block, which resembles nondepolarizing block.
Phase I block is potentiated by cholinesterase inhibitors and can be reversed by nondepolarizing neuromuscular blocking agents; fully established phase II block can be reversed by cholinesterase inhibitors and potentiated by nondepolarizing agents.
Stimulates cardiac vagus and subsequently sympathetic ganglia.
Advice to Patients
Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.
Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses (e.g., cardiovascular disease, neuromuscular disease).
Importance of informing patients of other important precautionary information. (See Cautions.)
Preparations
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Remember, keep this and all other medicines out of the reach of children,
never share your medicines with others, and use this medication only for the indication prescribed.
