Pharmacology · Neuromuscular blockers
Rocuronium !
Non-depolarising muscle relaxant with fast onset and intermediate duration. Sugammadex reverses it even from a deep block.
Updated 2026-11-01
Also called: Rocuronium bromide
The figure shows rocuronium bound to the muscle-type nicotinic receptor of the Torpedo ray (Tetronarce), a model of the human receptor, in a resting state.
Mechanism of action
Rocuronium, an aminosteroid, competes with acetylcholine for nicotinic receptors at the motor end plate without activating them. With fewer receptors available, the end-plate potential does not reach threshold and the muscle does not contract. The block is competitive: it is reversed by raising acetylcholine with an acetylcholinesterase inhibitor (neostigmine) or by removing rocuronium with sugammadex.
- Occupies the acetylcholine site on the nicotinic receptor
- The receptor does not open: the end-plate potential falls short
- Flaccid paralysis without fasciculations
- Reversal: neostigmine (more acetylcholine) or sugammadex (encapsulates it)
Pharmacokinetics
- Distribution
- In patients with slow circulation (older adults, heart disease) onset is delayed.
- Elimination
- Mainly hepatic and biliary; liver failure prolongs the effect.
- Onset and duration
- Fast, depending on the dose; that is why it serves for rapid sequence intubation when suxamethonium is contraindicated.
Indications
- Tracheal intubation, including rapid sequence intubation
- Muscle relaxation during surgery
- Facilitating mechanical ventilation
Adverse effects
Common
- Tachycardia
- Arrhythmias and ECG changes
- Residual block on waking
Contraindications
- Hypersensitivity to rocuronium or other neuromuscular blockers
Key interactions
- Halogenated agents (isoflurane, sevoflurane)
- Prolong and enhance the block.
- Aminoglycosides, vancomycin, tetracyclines, polymyxins
- Enhance the block.
- Magnesium sulfate (pre-eclampsia), lithium, quinidine, local anaesthetics
- Deeper and longer block.
- Chronic carbamazepine or phenytoin
- Resistance: the block is weaker or shorter.
- Alkaline solutions (barbiturates)
- Incompatible in the same syringe or line: they precipitate.
What is monitored
- Peripheral nerve stimulator (train-of-four) during use and before extubation
- Ventilation and saturation
- Signs of recovery: sustained head lift, good phonation, patent airway
Administration and safety
- Paralysing agent: store apart with a warning label; confirm the product before use.
- Always with adequate sedation or anaesthesia: it has no sedative or analgesic effect.
- Do not mix with alkaline solutions such as thiopental.
- If it extravasates, stop and continue in another vein.
Nursing care
- Before: check that ventilation is available, sedation is prescribed and sugammadex or neostigmine is at hand.
- During: train-of-four and regular assessment of sedation (a paralysed patient cannot show pain or distress).
- Protect the eyes (lubrication, closure) and reposition to prevent pressure injuries.
- After reversal: watch strength, breathing and saturation in case the block returns.
Pregnancy and breastfeeding
It has been used for caesarean sections, but the label does not recommend it for rapid sequence intubation in caesarean section; magnesium sulfate prolongs its effect.
Test yourself
Think of the answer, then tap the question to see it.
What advantage does rocuronium have over other non-depolarising agents in an urgent intubation?
Its onset is fast and sugammadex can reverse it immediately, even from a deep block.
Why does magnesium sulfate in a patient with pre-eclampsia prolong the block?
Magnesium reduces acetylcholine release and end-plate excitability, adding to the competitive block.
Which neuromuscular complication is linked to prolonged blockers in the ICU, especially with corticosteroids?
A myopathy with prolonged weakness (critical illness polyneuromyopathy).
How does rocuronium block differ from suxamethonium phase I block on train-of-four?
Rocuronium produces fade of successive responses; suxamethonium in phase I reduces them all equally without fade.
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 - ROCURONIUM BROMIDE injection, solution (DailyMed (U.S. National Library of Medicine), 2026); DailyMed - SUGAMMADEX 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); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.