FRCA Notes


Rocuronium


  • Rocuronium is a monoquaternary aminosteroid that was developed from vecuronium and has the main advantage of rapid onset
Rocuronium chemical structure
  • Standard induction of anaesthesia: 0.6mg/kg provides intubating conditions in 100-120s
  • Rapid sequence induction: 1.2mg/kg provides intubating conditions in 60-90s, owing to low potency
  • Duration of effect approximately 30-40mins, but is dependent on initial dose as well as patient factors such as hepatic or renal impairment

  • Presents as the bromide salt i.e. rocuronium bromide
  • Colourless solution stored in glass vials at 4'C (i.e. fridge)
  • Concentration of 10mg/ml

Distribution

  • 30% protein bound
  • Low volume of distribution

Metabolism and excretion

  • Mainly (30%) excreted unchanged in the bile
  • A smaller proportion is excreted unchanged in urine
  • Some hepatic de-acetylation occurs

  • A small degree of variability in required rocuronium dose (4%) is due to polymorphisms of the gene encoding the OATP1A2 uptake transporter (BJA, 2021)
  • Use of magnesium at a dose of 30-50mg/kg can reduce required rocuronium dose by up to 25%

  • Hepatic and renal failure will prolong duration of action

Cardiovascular

  • Minimal cardiovascular effects compared to other aminosteroids
  • RSI doses can contribute to tachycardia

Adverse effects

  • Does not cause histamine release
  • Pain on injection owing to low pH of solution (approximately 4)
  • Anaphylaxis