What is Atracurium Besylate Injection Used For?

October 8, 2025 •

5 min read

First approved for medical use in the United States in 1983, atracurium besylate is an intermediate-acting neuromuscular blocking agent. It is primarily used as an adjunct to general anesthesia to produce skeletal muscle relaxation, facilitate endotracheal intubation, and aid in mechanical ventilation in intensive care unit (ICU) patients.

Quick Summary

Atracurium besylate is an injectable muscle relaxant that works by blocking nerve signals at the neuromuscular junction. It is used alongside general anesthesia during surgical procedures and to assist with mechanical ventilation in critical care settings, providing controlled muscle paralysis.

Key Points

Skeletal Muscle Relaxation: Atracurium besylate injection is used to relax skeletal muscles during surgery as an adjunct to general anesthesia.
Endotracheal Intubation: It is administered to facilitate the insertion of an endotracheal tube for airway management.
Mechanical Ventilation: In Intensive Care Units (ICUs), atracurium is used to provide skeletal muscle relaxation for patients on mechanical ventilation.
Organ-Independent Metabolism: A key advantage is its metabolism via Hofmann elimination and ester hydrolysis, which does not rely on normal kidney or liver function.
Non-Depolarizing Blocker: It works by competitively blocking acetylcholine receptors at the neuromuscular junction, preventing muscle contraction.
Histamine Release: A potential dose-dependent side effect is the release of histamine, which can cause flushing and a transient drop in blood pressure.
Professional Administration Only: As a paralytic, it must be administered by or under the supervision of skilled professionals with access to respiratory support equipment.

What is Atracurium Besylate?

Atracurium besylate is a non-depolarizing neuromuscular blocking agent belonging to the benzylisoquinolinium class of drugs. It is administered intravenously by healthcare professionals, such as anesthesiologists, and is considered a 'high-alert' medication due to its potential for causing respiratory paralysis. The drug's effects last for a moderate duration, making it a versatile tool in controlled medical environments like operating rooms and intensive care units. It is crucial to remember that atracurium does not have any effect on consciousness or pain perception, so it must always be used in conjunction with appropriate anesthesia or sedation.

Mechanism of Action

Atracurium works by competitively blocking the nicotinic acetylcholine receptors located at the motor endplate of skeletal muscles. Normally, the neurotransmitter acetylcholine binds to these receptors to trigger muscle contraction. By preventing this binding, atracurium interrupts the signal from the nerves, causing muscle paralysis. This process is reversible, and the effects can be terminated pharmacologically with anticholinesterase agents like neostigmine once the procedure is complete.

Unique Metabolism via Hofmann Elimination

One of the most notable features of atracurium is its unique metabolic pathway. Instead of relying heavily on the liver or kidneys for clearance, atracurium is spontaneously degraded in the bloodstream through two non-oxidative processes:

Hofmann elimination: A non-enzymatic chemical reaction that occurs at physiological pH and temperature, breaking down the drug. This is the principal route of elimination.
Ester hydrolysis: Breakdown by non-specific esterases in the plasma.

This organ-independent metabolism is particularly beneficial for patients with impaired renal or hepatic function, as they can receive treatment without the risk of drug accumulation or prolonged paralysis. The main metabolite, laudanosine, has no neuromuscular blocking properties but can act as a central nervous system (CNS) stimulant and may accumulate in patients with long-term atracurium infusions, particularly in the ICU.

Primary Medical Applications

Atracurium besylate injection is used in several critical medical situations where muscle paralysis is necessary for safety and procedural efficacy:

General Anesthesia: As an adjunct to general anesthesia, it ensures total muscle relaxation during surgery, allowing for better access to surgical sites and preventing patient movement.
Endotracheal Intubation: The injection provides the necessary muscle relaxation to facilitate the safe and efficient placement of a breathing tube into the trachea. While effective, it has a slightly longer onset of action than other agents like succinylcholine for emergency intubation.
Mechanical Ventilation: In the Intensive Care Unit (ICU), atracurium is used for prolonged periods to manage mechanically ventilated patients. This reduces patient agitation, minimizes oxygen consumption, and prevents the patient from fighting the ventilator.

Administration

Atracurium is administered exclusively intravenously, either as a bolus or a continuous infusion. Intramuscular administration is strictly contraindicated due to the potential for severe tissue irritation. The amount administered is highly individualized based on the patient's weight, age, the type of anesthesia used, and the desired duration of muscle relaxation.

Administration is based on patient factors and the specific medical procedure.
For extended procedures or mechanically ventilated patients, continuous infusion is often used, with the rate adjusted based on the patient's response and clinical monitoring.

Side Effects and Risks

Like all medications, atracurium besylate carries a risk of side effects, which require careful monitoring:

Histamine Release: A dose-dependent release of histamine can cause transient hypotension (low blood pressure) and flushing of the skin. This risk is managed by slow administration and adjustments, especially in patients with cardiovascular disease or asthma.
Anaphylaxis: Severe allergic reactions, although rare, can be life-threatening and require immediate medical intervention.
Cardiovascular Effects: While generally minimal, some patients may experience changes in heart rate, including bradycardia or tachycardia.
Prolonged Paralysis: This may occur in some individuals, particularly after long-term use in the ICU or in patients with certain neuromuscular diseases.
Seizures: Accumulation of the metabolite laudanosine during prolonged high-dose infusions has been associated with seizures in animal studies. While rare, it warrants caution in susceptible ICU patients.

Comparison: Atracurium vs. Other Muscle Relaxants

Different neuromuscular blocking agents are available, and the choice depends on the patient's medical condition and the procedural requirements. Here is a comparison of atracurium with some common alternatives:


Feature	Atracurium Besylate	Cisatracurium	Vecuronium	Succinylcholine
Class	Non-depolarizing	Non-depolarizing	Non-depolarizing	Depolarizing
Duration	Intermediate	Intermediate	Intermediate	Very Short
Metabolism	Organ-independent (Hofmann elimination)	Organ-independent (Hofmann elimination)	Primarily hepatic	Enzymatic (plasma cholinesterase)
Renal/Hepatic Failure	Typically no dose adjustment needed	Typically no dose adjustment needed	May require dose adjustment	Not significantly affected
Histamine Release	Potential, dose-dependent	Minimal	Minimal to none	Minimal
Cardiovascular Effects	Minimal at recommended use (potential for hypotension)	Stable hemodynamics	Minimal	Potential for bradycardia or tachycardia
Use in Intubation	Suitable for non-emergency	Suitable for non-emergency	Suitable	Preferred for rapid sequence

Precautions and Contraindications

Before administration, healthcare providers must carefully assess the patient's medical history and current health status. Key precautions and contraindications include:

Hypersensitivity: Atracurium is contraindicated in patients with a known hypersensitivity to the drug or cisatracurium.
Neuromuscular Disease: Conditions like myasthenia gravis or Lambert-Eaton syndrome increase a patient's sensitivity to muscle relaxants, requiring careful management and monitoring.
Cardiovascular Disease: Patients with significant cardiovascular disease may be sensitive to potential histamine release, requiring slower administration.
Burn Patients: Individuals with extensive burns can develop resistance to non-depolarizing muscle relaxants and may require adjustments in administration.
Use in ICU: For prolonged infusion in ICU patients, continuous neuromuscular monitoring is essential to avoid excessive administration and assess recovery.

Conclusion

Atracurium besylate injection is a reliable and predictable neuromuscular blocking agent that plays a critical role in modern anesthesia and critical care. Its unique organ-independent metabolism is a significant advantage, particularly for patients with compromised liver or kidney function. Used primarily to facilitate surgery, endotracheal intubation, and mechanical ventilation, atracurium provides controlled muscle relaxation and is a cornerstone of safe and effective airway management in a variety of clinical scenarios. Its effects are carefully monitored to ensure patient safety and can be reversed pharmacologically at the end of a procedure. All uses must be managed by trained medical professionals who are equipped to handle the potential risks, including respiratory paralysis.

For more detailed information on contraindications and drug interactions, refer to the Pfizer Medical Information page for atracurium besylate.

Frequently Asked Questions

Atracurium besylate is primarily used to provide skeletal muscle relaxation during surgery, to assist with endotracheal intubation, and to facilitate mechanical ventilation in critically ill patients.

Unlike many other muscle relaxants that depend on the liver and kidneys for elimination, atracurium undergoes spontaneous breakdown in the bloodstream through a process called Hofmann elimination. This makes it particularly suitable for patients with hepatic or renal impairment.

Yes, because its metabolism is independent of organ function, atracurium can be used for patients with liver or kidney failure, often without requiring dosage adjustments.

No, atracurium is a paralytic agent that only affects skeletal muscles. It does not cause sedation, affect consciousness, or relieve pain. It must be used alongside adequate general anesthesia or sedation.

Common side effects include flushing and mild, transient hypotension, which are associated with dose-dependent histamine release. More serious, but rare, side effects include severe allergic reactions (anaphylaxis).

It is contraindicated in patients with a known hypersensitivity to atracurium or cisatracurium. Caution is also advised for patients with significant cardiovascular disease, asthma, severe electrolyte disorders, or specific neuromuscular diseases like myasthenia gravis.

Atracurium is administered intravenously, either as a bolus injection or as a continuous infusion. It must not be given by intramuscular injection, as it can cause excessive tissue irritation.

Yes, the neuromuscular block induced by atracurium can be reversed pharmacologically using an anticholinesterase agent, such as neostigmine, often in conjunction with an anticholinergic agent like atropine to counteract side effects.