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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Other
Succinylcholine is a depolarizing neuromuscular blocking agent used to induce muscle relaxation during surgery and mechanical ventilation. It belongs to the class of skeletal muscle relaxants and is known for its rapid onset and ultra-short duration of action.
Name
Succinylcholine
Raw Name
SUCCINYLCHOLINE CHLORIDE
Category
Other
Salt Form
Chloride
Drug Count
4
Variant Count
42
Last Verified
February 17, 2026
RxCUI
1594589, 1594591, 2598128, 1594585, 1594587, 1594593, 2694114
UNII
I9L0DDD30I, 8L0S1G435E
About Succinylcholine
Succinylcholine is a depolarizing neuromuscular blocking agent used to induce muscle relaxation during surgery and mechanical ventilation. It belongs to the class of skeletal muscle relaxants and is known for its rapid onset and ultra-short duration of action.
Detailed information about Succinylcholine
This page is for informational purposes only and does not replace medical advice. Consult a qualified healthcare professional before using any medication containing Succinylcholine.
Succinylcholine (also known as succinylcholine chloride) is a high-potency, depolarizing neuromuscular blocking agent (NMBA) that has been a cornerstone of clinical anesthesia since its FDA approval in 1952. It is pharmacologically classified as a skeletal muscle relaxant. Unlike non-depolarizing agents (such as rocuronium or vecuronium), succinylcholine works by mimicking the action of acetylcholine at the neuromuscular junction but for a more prolonged period. This results in a persistent depolarization of the motor endplate, leading to skeletal muscle paralysis. Because of its unique pharmacokinetic profile—specifically its ultra-rapid onset (30–60 seconds) and ultra-short duration of action (4–10 minutes)—it is the gold standard for rapid sequence induction (RSI) and intubation in emergency settings where securing an airway quickly is life-saving.
In patient-friendly terms, succinylcholine acts as a chemical 'switch' that temporarily turns off the communication between nerves and muscles. This allows healthcare providers to insert breathing tubes without the patient’s natural gag reflex or muscle tension interfering with the procedure. It is primarily used in hospital settings, emergency departments, and surgical suites under the direct supervision of an anesthesiologist or emergency physician.
At the molecular level, succinylcholine is composed of two joined molecules of acetylcholine. When injected intravenously, it travels to the neuromuscular junction (the space where a nerve meets a muscle) and binds to nicotinic acetylcholine receptors on the motor endplate.
Normally, acetylcholine binds briefly to these receptors, causes a contraction, and is immediately broken down by the enzyme acetylcholinesterase. Succinylcholine, however, is not broken down by acetylcholinesterase. Instead, it stays bound to the receptor, causing an initial wave of muscle contractions known as 'fasciculations' (which often look like small twitches under the skin). After this initial stimulation, the muscle becomes unresponsive to further nerve signals because the endplate remains depolarized and cannot 'reset' (repolarize). This state is known as a Phase I block. In higher doses or with prolonged exposure, it can transition into a Phase II block, which resembles the action of non-depolarizing relaxants. Paralysis occurs in a predictable order: starting with the small muscles of the face and fingers, moving to the limbs and trunk, and finally affecting the diaphragm and intercostal muscles used for breathing.
Understanding how the body processes succinylcholine is vital for clinical safety.
Succinylcholine is FDA-approved for several specific indications where rapid muscle relaxation is required:
Succinylcholine is available exclusively as an injectable solution. It is typically supplied in concentrations of 20 mg/mL, 50 mg/mL, or 100 mg/mL in multi-dose vials or pre-filled syringes. It must be stored under refrigeration (2°C to 8°C or 36°F to 46°F) to maintain its potency, although some formulations are stable at room temperature for short periods.
> Important: Only your healthcare provider can determine if Succinylcholine is right for your specific condition. It is never self-administered and is only used in controlled medical environments.
Dosage for succinylcholine is highly individualized based on the patient's body weight, the desired depth of relaxation, and the specific clinical procedure. For the average adult, the standard dose for endotracheal intubation is 0.6 mg/kg to 1.1 mg/kg administered intravenously. The typical dose for a 70 kg adult is approximately 70 mg to 100 mg. For short surgical procedures, smaller intermittent doses of 0.04 mg/kg to 0.07 mg/kg may be used to maintain relaxation. If administered via continuous infusion, the rate is usually 0.5 mg to 10 mg per minute, though this requires constant monitoring with a nerve stimulator to prevent overdose.
In pediatric patients, succinylcholine is generally reserved for emergency intubation or instances where an immediate airway must be secured. The FDA has issued a warning regarding its use in children due to the risk of undiagnosed myopathies (muscle diseases) leading to fatal hyperkalemia (high potassium).
Succinylcholine should be used with extreme caution in patients with chronic renal failure, especially those with pre-existing high potassium levels. While the drug's metabolism is not dependent on the kidneys, the rise in serum potassium (typically 0.5 mEq/L) that occurs with administration can be dangerous in patients who already have impaired potassium excretion.
Patients with severe liver disease may have reduced levels of pseudocholinesterase (the enzyme that breaks down the drug). This can lead to a significantly prolonged duration of paralysis, requiring the patient to remain on a ventilator longer than expected.
Older adults may have a slightly slower onset of action due to reduced cardiac output and circulation time. Additionally, they are more likely to be taking concurrent medications that could interact with succinylcholine.
Succinylcholine is administered only by trained healthcare professionals (anesthesiologists, CRNAs, or emergency physicians). It is given as a rapid bolus injection into a functioning intravenous line. Because it paralyzes the muscles used for breathing, it is only administered after the medical team has confirmed they have the equipment and expertise to provide artificial ventilation (oxygenation) for the patient. It is never used outside of a hospital or emergency setting.
Because succinylcholine is a one-time medication administered for a specific procedure by a doctor, there is no risk of a 'missed dose' in the traditional sense. If a procedure is delayed, the medical team will adjust the timing of the administration accordingly.
An overdose of succinylcholine results in prolonged muscle paralysis and apnea (the inability to breathe). Because there is no direct pharmacological reversal agent for succinylcholine (unlike non-depolarizing agents), the treatment for overdose is purely supportive. The patient must be kept sedated and on a mechanical ventilator until the body's natural enzymes break down the drug and muscle function returns. Signs of overdose include extended duration of block and, in rare cases, the transition to a Phase II block.
> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance. In the case of succinylcholine, the 'dose' is entirely managed by your surgical or emergency team.
Succinylcholine is associated with several physiological changes that occur as a direct result of its mechanism of action.
> Warning: Succinylcholine is administered in a hospital where these effects are monitored. However, if you are recovering from surgery and notice these symptoms, alert medical staff immediately.
Succinylcholine is an ultra-short-acting drug intended for single-use or very short-term use. There are no known chronic or 'long-term' side effects from a single administration, other than the potential for temporary muscle soreness or the rare complication of kidney injury if rhabdomyolysis occurred during the procedure.
The FDA has issued a Black Box Warning for succinylcholine regarding its use in children and adolescents. There have been reports of rare, sudden cardiac arrest caused by extremely high potassium levels (hyperkalemia) in seemingly healthy children who were later found to have undiagnosed skeletal muscle myopathies, most commonly Duchenne Muscular Dystrophy. Because these conditions are often not diagnosed until the child is older, the use of succinylcholine in pediatric patients should be reserved for emergency intubation or cases where the immediate securing of an airway is necessary.
Report any unusual symptoms to your healthcare provider.
Succinylcholine is a high-alert medication that must only be used by clinicians who are experts in airway management and cardiopulmonary resuscitation. Because it causes total respiratory paralysis, the patient will stop breathing entirely within seconds of administration. Immediate access to oxygen, manual ventilation equipment, and intubation tools is mandatory. Furthermore, the drug should never be used without adequate sedation or anesthesia, as the patient will be paralyzed but fully conscious and able to feel pain if not properly anesthetized.
Pediatric Hyperkalemia Warning: As detailed in the side effects section, succinylcholine is associated with a risk of fatal cardiac arrest in children with undiagnosed muscular dystrophy. The FDA mandates that its use in children be limited to emergency situations where non-depolarizing relaxants are not suitable.
Patients receiving succinylcholine require continuous, high-level monitoring, including:
Because succinylcholine is used as part of general anesthesia, patients must not drive or operate machinery for at least 24 hours after their procedure. The residual effects of the anesthetic gases and sedatives used alongside succinylcholine significantly impair cognitive and motor function.
Alcohol should be avoided for at least 24 hours before and after the administration of succinylcholine. Alcohol can potentiate the effects of general anesthetics and may interfere with the body's ability to recover from the procedure.
Succinylcholine is not a chronic medication; it is a single-use drug. There is no 'tapering' required, and there is no risk of withdrawal. Recovery occurs spontaneously as the drug is metabolized by plasma enzymes.
> Important: Discuss all your medical conditions with your healthcare provider before starting Succinylcholine.
While few drugs are strictly 'contraindicated' in an emergency, the following combinations significantly increase the risk of toxicity:
Since succinylcholine is administered intravenously in a clinical setting, food interactions are generally not a concern. However, patients are typically required to be 'NPO' (nothing by mouth) for several hours before surgery to prevent aspiration, which is the very complication succinylcholine is often used to manage during intubation.
For each major interaction, the management strategy usually involves the anesthesiologist adjusting the dose or extending the period of mechanical ventilation until the patient's muscle strength fully returns.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking.
Succinylcholine must NEVER be used in the following circumstances:
Conditions requiring careful risk-benefit analysis include:
Patients who are allergic to other neuromuscular blockers (like rocuronium or atracurium) may have a cross-sensitivity to succinylcholine. Anesthesiologists must be prepared for potential anaphylaxis in any patient with a history of 'quaternary ammonium' allergies.
> Important: Your healthcare provider will evaluate your complete medical history before prescribing Succinylcholine.
Succinylcholine is classified as FDA Pregnancy Category C. This means that while animal studies may have shown an adverse effect, there are no adequate, well-controlled studies in humans. However, it is frequently used in clinical practice for emergency Cesarean sections because it does not cross the placental barrier in significant amounts and therefore does not paralyze the baby. Its rapid onset is highly beneficial when a mother's airway must be secured quickly to prevent aspiration.
It is unknown whether succinylcholine is excreted in human milk. However, because the drug has an extremely short half-life (minutes) and is rapidly broken down in the mother's bloodstream, it is highly unlikely that any significant amount would reach the infant through breast milk. Most clinical guidelines suggest that breastfeeding can be safely resumed once the mother has fully recovered from the effects of anesthesia.
As noted in the Black Box Warning, pediatric use is restricted. Succinylcholine should only be used in children for emergency intubation or when other options are unavailable. The risk of undiagnosed muscular dystrophy leading to fatal hyperkalemia is the primary concern. When used, it is often preceded by atropine to prevent the profound bradycardia (slow heart rate) that children often experience with this drug.
Elderly patients may be more sensitive to the cardiovascular effects of succinylcholine, such as changes in heart rate or blood pressure. They are also more likely to have underlying renal or hepatic issues that could slightly alter the drug's profile. However, age itself is not a contraindication, and the drug is used safely in the elderly for procedures like ECT.
In patients with kidney failure, the primary concern is not the clearance of the drug itself, but the management of potassium. If the patient is well-dialyzed and has a normal potassium level, succinylcholine can be used. If the patient is hyperkalemic, it must be avoided.
Patients with severe liver cirrhosis or liver failure may have low levels of plasma cholinesterase. This does not prevent the use of the drug, but the medical team must be prepared for the paralysis to last significantly longer (e.g., 20–30 minutes instead of 5–10 minutes).
> Important: Special populations require individualized medical assessment.
Succinylcholine is a depolarizing neuromuscular blocker. It acts as an agonist at the nicotinic acetylcholine receptors located on the motor endplate of the neuromuscular junction. By binding to these receptors, it causes a persistent depolarization of the muscle cell membrane. This prevents the muscle from repolarizing and responding to subsequent pulses of acetylcholine, resulting in flaccid paralysis. This is referred to as a Phase I block.
The onset of action is the fastest of all known neuromuscular blockers, typically occurring within 30 to 60 seconds after IV administration. The duration of the clinical block is short, usually lasting 4 to 10 minutes. The recovery of muscle strength follows a predictable pattern, with the diaphragm being the first to recover.
| Parameter | Value |
|---|---|
| Bioavailability | 100% (IV) |
| Protein Binding | Minimal |
| Half-life | < 1 minute |
| Tmax | 30-60 seconds |
| Metabolism | Plasma Cholinesterase (90%) |
| Excretion | Renal (Metabolites) |
Succinylcholine is the only depolarizing neuromuscular blocking agent currently in widespread clinical use. It is distinct from non-depolarizing agents like the benzylisoquinolines (atracurium) or amino-steroids (rocuronium).
Medications containing this ingredient
Common questions about Succinylcholine
Succinylcholine is primarily used in the hospital setting to produce rapid, short-term muscle paralysis. Its most common application is to facilitate endotracheal intubation, which involves placing a breathing tube into a patient's windpipe during surgery or emergency situations. Because it works so quickly, it is the preferred choice for 'Rapid Sequence Induction' when a patient needs to be put on a ventilator immediately. It is also used during electroconvulsive therapy (ECT) to prevent muscle injury during the procedure. Only a qualified medical professional can administer this medication.
The most frequent side effect is postoperative muscle pain, known as myalgia, which can feel like severe soreness after exercise. This occurs because the drug causes muscles to twitch or 'fasciculate' before they become paralyzed. Other common effects include a temporary increase in pressure within the eye and a slight slowing of the heart rate, especially in children. Some patients may also experience increased salivation or a temporary skin rash. These effects are usually transient and are managed by the anesthesia team during and after your procedure.
You should not consume alcohol for at least 24 hours before or after receiving succinylcholine. Since this drug is only used during surgical procedures involving general anesthesia, alcohol can dangerously interact with the other sedatives and anesthetic gases used. Alcohol can also impair your recovery and increase the risk of complications like nausea or respiratory depression. Always follow the specific fasting and pre-operative instructions provided by your surgical team. If you have consumed alcohol recently, it is vital to inform your anesthesiologist before the procedure begins.
Succinylcholine is often used during pregnancy, particularly for emergency Cesarean sections, because it does not cross the placenta in amounts that would affect the baby. While it is classified as Category C by the FDA, its benefits in securing a mother's airway quickly often outweigh the theoretical risks. The drug is broken down so rapidly in the mother's blood that very little reaches the fetus. However, like all medications during pregnancy, its use is carefully considered by the medical team based on the urgency of the situation. Always discuss any concerns with your obstetrician or anesthesiologist.
Succinylcholine is known for having the fastest onset of any muscle relaxant used in medicine. When administered intravenously, it typically produces complete muscle paralysis within 30 to 60 seconds. This rapid action is why it is the 'gold standard' for emergency situations where a doctor must secure a patient's airway as quickly as possible. The effects are also very short-lived, usually wearing off within 4 to 10 minutes as the body's natural enzymes break the drug down. This allows for a quick return to normal breathing once the procedure is finished.
Succinylcholine is not a medication that you take on a regular basis, so the concept of 'stopping' it does not apply in the traditional sense. It is a one-time injection given by a doctor for a specific medical procedure. Once the injection is given, the body naturally clears the drug within a few minutes. There are no withdrawal symptoms or long-term dependency issues associated with its use. If you have concerns about how you reacted to the drug during a past surgery, you should discuss this with your doctor before any future procedures.
It is impossible to miss a dose of succinylcholine because it is not a self-administered medication. It is only given by healthcare professionals in a hospital or emergency setting. The timing and dosage are strictly controlled by the anesthesiologist based on the requirements of your surgery or treatment. If a procedure is rescheduled, the administration of the drug is simply moved to the new time. You do not need to worry about tracking doses or schedules for this medication as it is entirely managed by your clinical team.
No, succinylcholine does not cause weight gain. It is an ultra-short-acting medication that remains in the body for only a few minutes. Because it is not used for chronic or long-term treatment, it has no impact on metabolism, appetite, or fat storage. Any weight changes you might experience after a surgery are more likely related to IV fluids, post-operative inflammation, or changes in activity levels during recovery. If you notice significant weight changes after a hospital stay, you should consult your primary care physician to determine the underlying cause.
Succinylcholine can interact with several other medications, which is why your anesthesiologist will ask for a complete list of your current drugs. Certain antibiotics, heart medications, and even eye drops can prolong the effects of succinylcholine, potentially leading to a longer period of paralysis than intended. It is especially important to mention if you take lithium, magnesium, or any medications for glaucoma. Your medical team is trained to adjust the anesthesia plan based on these interactions to ensure your safety. Never hide any medication or supplement use from your surgical team.
Yes, succinylcholine chloride is available as a generic medication and is produced by several different pharmaceutical manufacturers. It has been available as a generic for many decades, which helps keep the cost of the medication relatively low for hospitals and surgical centers. While it may be sold under brand names like Anectine or Quelicin in some regions, the active ingredient remains the same. Regardless of the manufacturer, the drug must meet strict FDA standards for purity and potency. Your hospital will use the version that is currently in their pharmacy stock.