Rocuronium-induced neuromuscular blockade can be rapidly and completely reversed by sugammadex through which mechanism?
- A Competitive displacement of rocuronium from nicotinic receptors at the NMJ
- B Inhibition of plasma cholinesterase to prolong the effect of acetylcholine
- C Encapsulation of rocuronium molecules in a modified gamma-cyclodextrin cavity, removing free drug from plasma ✓
- D Stimulation of nicotinic receptors to overcome competitive blockade
Correct answer: C. Encapsulation of rocuronium molecules in a modified gamma-cyclodextrin cavity, removing free drug from plasma
Explanation
Sugammadex is a modified gamma-cyclodextrin that forms a tight 1:1 inclusion complex with rocuronium (and vecuronium) in plasma, effectively encapsulating the drug molecule within its lipophilic core. This rapidly reduces free plasma rocuronium concentration, drawing drug away from the NMJ into plasma down the concentration gradient, leading to complete reversal within minutes — without needing anticholinesterases or muscarinic side effects.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.