A patient receives rocuronium for neuromuscular blockade during surgery. At the end of the procedure, the anaesthetist administers sugammadex for reversal. Which of the following best describes the mechanism by which sugammadex reverses rocuronium-induced neuromuscular blockade?

• A It inhibits acetylcholinesterase, increasing acetylcholine at the neuromuscular junction
• B It encapsulates the rocuronium molecule, rendering it unavailable to bind receptors ✓
• C It acts as a competitive antagonist at the nicotinic acetylcholine receptor
• D It enhances hepatic metabolism of rocuronium via cytochrome P450 induction

Explanation

Sugammadex is a modified gamma-cyclodextrin that encapsulates steroidal neuromuscular blocking agents such as rocuronium and vecuronium, forming a tight complex that renders the relaxant unable to bind to the acetylcholine receptor. This is a chelation-based mechanism rather than a pharmacological reversal. Option A describes neostigmine. Sugammadex cannot reverse benzylisoquinolinium agents like atracurium or cisatracurium.

Reference: Miller's Anaesthesia, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.