Cisatracurium (formerly recognized as 51W89, and marketed as Nimbex) is a neuromuscular-blocking drug or skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. It is a bisbenzyltetrahydroisoquinolinium agent with an intermediate duration of action. Cisatracurium is one of the ten isomers of the parent molecule, atracurium. Moreover, cisatracurium represents approximately 15% of the atracurium mixture.

Cisatracurium (formerly recognized as 51W89, and marketed as Nimbex) is a neuromuscular-blocking drug or skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to facilitate endotracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation. It is a bisbenzyltetrahydroisoquinolinium agent with an intermediate duration of action. Cisatracurium is one of the ten isomers of the parent molecule, atracurium. Moreover, cisatracurium represents approximately 15% of the atracurium mixture.