Rocuronium is an aminosteroid non-depolarizing neuromuscular blocker or muscle relaxant used in modern anaesthesia, to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. It was designed to be a weaker antagonist at the neuromuscular junction than pancuronium; hence its monoquaternary structure and its having an allyyl group and a pyrrolidine group attached to the D ring quaternary nitrogen atom. Introduced in 1994, rocuronium has rapid onset, and intermediate duration of action. The γ-cyclodextrin derivative sugammadex (trade name Bridion) has been recently introduced as a novel agent to reverse the action of rocuronium. There is considered to be a risk of allergic reaction to the drug in some patients, but a similar incidence of allergic reactions has been observed by using other members of the same drug class.