Anaesthesia · Muscle Relaxants (Depolarizing and Non-Depolarizing)

Rocuronium 0.6 mg/kg is used for tracheal intubation. Compared to succinylcholine 1 mg/kg, the onset of action of rocuronium at this dose is approximately:

  • A 15-30 seconds
  • B 90-120 seconds
  • C 45-60 seconds
  • D 3-4 minutes
Correct answer: B. 90-120 seconds

Explanation

Rocuronium at 0.6 mg/kg has an onset of approximately 90-120 seconds. Succinylcholine at 1 mg/kg acts within 45-60 seconds. Rocuronium's lower potency (requires a larger molecular dose to achieve the same effect) accounts for its slower onset. At 1.2 mg/kg (RSI dose), rocuronium onset approaches that of succinylcholine.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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