We describe ultra-short, short, and intermediate duration neuromuscular blocking compounds, reversible by cysteine or similar compounds, that are bisquaternary diesters of chlorofumaric, fumaric, or maleic acids where the quaternary groups are very different, creating a highly asymmetrical molecule where one quaternary includes an isoquinolinium ring system and the other includes a morpholinium, piperidinium, piperazinium, or pyrrolidinium system, pharmaceutical compositions, methods to use such compounds and compositions, and kits.
