Pharmacology · Neuromuscular blockers
Atracurium !
Non-depolarising muscle relaxant that breaks down by itself in the blood (Hofmann elimination): useful in liver or kidney failure. It releases histamine.
Updated 2026-11-01
Also called: Atracurium besilate
There is no structure with atracurium. The figure shows d-tubocurarine, another benzylisoquinoline, at the acetylcholine site of the Torpedo ray muscle-type nicotinic receptor.
Mechanism of action
Atracurium, a benzylisoquinoline, competes with acetylcholine at the nicotinic receptor of the motor end plate without activating it. Its distinctive feature is elimination: it breaks down in plasma by ester hydrolysis and by Hofmann elimination, a chemical process that does not depend on enzymes, the liver or the kidney and occurs at physiological pH. One of its products is laudanosine.
- Competes with acetylcholine at the nicotinic receptor
- Flaccid paralysis of intermediate duration
- Breaks down in blood (Hofmann and esters) without liver or kidney
- Releases histamine with high doses or rapid injection
Pharmacokinetics
- Metabolism
- Hofmann elimination (chemical, non-enzymatic) and hydrolysis by non-specific esterases; produces laudanosine.
- Elimination
- The metabolites leave in urine and bile; duration barely changes with renal or hepatic failure.
Indications
- Tracheal intubation and muscle relaxation in surgery
- Patients with liver or kidney failure who need neuromuscular block
Adverse effects
Common
- Skin flushing
- Transient hypotension
- Tachycardia
Contraindications
- Hypersensitivity to atracurium
- Multiple-dose vials with benzyl alcohol: hypersensitivity to benzyl alcohol; avoided in newborns
Key interactions
- Halogenated agents, aminoglycosides, magnesium, lithium
- Enhance the block.
- Alkaline solutions (barbiturates)
- Incompatible; atracurium is inactivated or precipitates.
What is monitored
- Train-of-four
- Blood pressure and signs of histamine release (flushing, bronchospasm)
- Ventilation and saturation
Administration and safety
- Keep refrigerated and protected from light; at room temperature it loses potency.
- In patients with heart disease or a history suggesting a higher risk of histamine release (asthma, anaphylactoid reactions), it is injected more slowly.
- Do not mix with alkaline solutions in the same syringe or line.
- Paralysing agent: store apart with warnings.
Nursing care
- Watch blood pressure, flushing and wheeze after injection.
- Train-of-four and sedation assessment.
- With long ICU infusions: watch for seizures.
- After reversal: strength, breathing and saturation.
Pregnancy and breastfeeding
Small amounts cross the placenta; it has been used for caesarean sections without attributable effects in the newborns, who are watched for respiratory depression.
Test yourself
Think of the answer, then tap the question to see it.
What is Hofmann elimination?
A spontaneous, non-enzymatic chemical breakdown that occurs in plasma at physiological pH; it eliminates atracurium and cisatracurium.
Why is atracurium useful in liver or kidney failure?
Its elimination does not depend on those organs: it breaks down in the blood by Hofmann elimination and esterases.
Which atracurium metabolite can cause cerebral excitation?
Laudanosine, which causes seizures at high doses in animals.
Related drugs
← Back to the class: Neuromuscular blockers
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - ATRACURIUM BESYLATE injection, solution (DailyMed (U.S. National Library of Medicine), 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 13 (McGraw Hill, 2023); eEML - Electronic Essential Medicines List (World Health Organization, 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.