Neuromuscular blocker
Rocuronium
Also called roc
Indications
- Rapid sequence intubation, especially when succinylcholine is contraindicated (hyperkalemia, burns or crush days old, denervation, myopathy, malignant hyperthermia risk)
- Routine tracheal intubation and relaxation during surgery
- Paralysis during mechanical ventilation for dyssynchrony, severe ARDS or raised ICP, by bolus or infusion; long-term ICU use is not well studied
- Refractory shivering during targeted temperature management (off-label)
Dosing
Rocuronium drip card and mL/h converterStart: 8–12 mcg/kg/min after an intubating dose
| Where | Dose |
|---|---|
| Airway and RSI | Rocuronium: 1–1.2 mg/kg for RSI (0.6 for routine); reverse with sugammadex 16 mg/kg |
On the quick cards
Mechanism of action
Rocuronium is a competitive antagonist at the postjunctional nicotinic acetylcholine receptor. It occupies the acetylcholine sites on the α subunits without opening the channel, and blocking one of the two sites keeps the channel shut, so the end-plate potential stays below threshold and the fiber does not contract. Block of prejunctional nicotinic receptors that mobilize acetylcholine causes fade with train-of-four and tetanic stimulation. Neostigmine can overcome the block by raising acetylcholine, and sugammadex ends it by encapsulating the drug.
Pharmacology
- Neuromuscular: intermediate-acting block with fade and post-tetanic potentiation; low potency (ED95 about 0.3 mg/kg) means many molecules are given, which speeds onset
- Cardiovascular: little effect; a slight vagolytic action at high doses may raise heart rate (more than vecuronium, less than pancuronium); no meaningful histamine release
- Respiratory: apnea once the diaphragm is blocked; no direct airway effect
- CNS: none; it does not cross the blood-brain barrier, so a paralyzed patient can be awake and in pain
- Other: potentiated by volatile anesthetics, aminoglycosides, vancomycin, magnesium, lithium, acidosis and hypothermia; resisted after burns or denervation and with chronic phenytoin or carbamazepine
Pharmacokinetics
| Onset | Maximal block 1.0 min after 1.2 mg/kg and 1.8 min after 0.6 mg/kg (label medians); intubating conditions in about 60–90 s |
|---|---|
| Duration | Clinical duration (to 25% recovery) about 31 min after 0.6 mg/kg and 58–67 min after 0.9–1.2 mg/kg; can exceed 2 h |
| Half-life | About 1.4 h in adults; 2.4 h in kidney failure and 4.3 h in liver dysfunction |
| Distribution | Vd about 0.25 L/kg (extracellular fluid), about double in liver disease; umbilical levels 18% of maternal |
| Protein binding | About 30% |
| Metabolism | Minimal; 17-desacetylrocuronium, with about a twentieth of the potency, is rarely detected |
| Clearance | About 0.25 L/kg/h (4 mL/kg/min), roughly halved in liver dysfunction and kidney failure |
| Elimination | Mainly hepatic uptake and biliary excretion of unchanged drug; up to about 40% appears in urine within 24 h |
| Organ failure | After a single dose, clinical duration is about 1.5 times longer in liver disease, similar in kidney failure and slightly longer in older adults |
Chemistry
- Monoquaternary aminosteroid on an androstane nucleus: a 2-morpholine ring (tertiary amine), a 3-hydroxyl, a 17-acetate and a charged 16-N-allyl pyrrolidinium head
- Derived from vecuronium: the 3-hydroxyl leaves no 3-desacetyl metabolite and keeps it stable in solution, and the changed side groups lower potency, which speeds onset
- Single isomer with the fixed stereochemistry of the steroid nucleus; the permanent charge makes it water soluble with little lipid solubility
- 10 mg/mL solution buffered to pH 4 with acetate and made isotonic with sodium chloride; precipitates with alkaline drugs such as thiopental and is incompatible in the line with others, including dexamethasone, furosemide, insulin and vancomycin
- Refrigerate at 2–8 °C; at room temperature use within 60 days, and opened vials within 30 days
Adverse effects and cautions
In the one-pagers
- Airway and RSIRSI drugs: Sugammadex reverses rocuronium or vecuronium; 16 mg/kg reverses rocuronium immediately. Watch for anaphylaxis, bradycardia; backup contraception for 7 days.
- Myasthenic Crisis and Guillain-Barré SyndromeNIV or intubation: MG: resists succinylcholine; deep, long block with rocuronium, so less drug, train-of-four, sugammadex
- Asthma and COPD ExacerbationsIntubating severe asthma: Rapid sequence: ketamine 1–2 mg/kg (bronchodilates, less hypotension) or propofol, with rocuronium 1–1.2 mg/kg or succinylcholine
- Mass Casualty Triage and Incident CommandCBRNE: decontamination, nerve agents and radiation: Nerve agents inhibit acetylcholinesterase. Vapor acts in seconds to minutes: miosis, rhinorrhea and chest tightness, then bronchorrhea, bronchospasm, fasciculations, seizures and apnea. Liquid on skin can take up to 18 hours to cause systemic effects (Merck 2026). In Tokyo, over 20% of St Luke's staff had symptoms of secondary exposure (Ohbu 1997
- Toxidromes and AntidotesCarbon monoxide, cyanide, methemoglobin and organophosphates: Organophosphates inhibit acetylcholinesterase, producing muscarinic, nicotinic (fasciculations, weakness, paralysis) and CNS effects. The inhibited enzyme 'ages' into a permanent form, while carbamates release it within about 48 h (Merck). Atropinize to a clear chest, HR over 80 and SBP over 80, then infuse 10–20% of the loading dose pe
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Sources
- FDA label: rocuronium bromide, Hospira (2025)
- Esmeron prescribing information, MSD (2019)
- PubChem: rocuronium
For education and exam preparation only. Follow your institution’s protocols. Typical adult values for study. Follow the order, the label and your institution's protocols.