Approaches to short-acting neuromuscular blocking agents: nonsymmetrical bis-tetrahydroisoquinolinium mono- and diesters.

Nonsymmetrical bisquaternary mono- and diesters combining the potency-enhancing properties of the (1R)-laudanosinium group with a second unhindered quaternary ammonium moiety have been studied as a means of promoting short action with high-potency neuromuscular block. Atracurium-related nonsymmetrical diesters showed high potency, freedom from vagal blockade at neuromuscular blocking doses, and short action. Nonsymmetrical monoesters were short acting but showed varying degrees of vagal block.