Cisatracurium-d6-20-methyl Dibenzenesulfonate is the labeled analog of Cisatracurium-20-methyl Dibenzenesulfonate (C496705), an impurity of Cisatracurium (C496700), an enantiomer of Atracurium Besylate (A794500), a neuromuscular blocking agent. It could be used in liver transplant patient with safety.