Ultrashort acting neuromuscular blocking agents of formula (I) which are useful as skeletal muscle relaxants during engergency intubation procedures, routine surgery and post-operative settings are disclosed. Wherein: X is halogen; h is from 1 to 2; Y is hydrogen or methoxy; Z1 and Z2 are methyl; W1 and W2 are carbon; and A is a pharmaceutically acceptable anion.
Ultra short acting neuromuscular blockers