Rapacuronium Bromide (Raplon) was introduced on August 18, 1999 as a possible replacement for succinylcholine as a rapid onset neuromuscular blocking agent. Sadly, things didn't go well for it when it was discovered that rapacuronium could cause fatal bronchospasms. It was withdrawn in March of 2001, less than 2 years after its release. Poor thing... :(
It is a steroid structured nondepolarizing neuromuscular blocking agent of rapid onset and short duration. The chemical formula is C37H61N2O4.