Rapacuronium has a rapid onset of action, minimal cardiovascular side effects, and a sho duration of action. It was withdrawn by the manufacturer following several repos of serious bronchospasm, including a few unexplained fatalities. Histamine release may have been a factor. Ref: Morgan, Jr. G.E., Mikhail M.S., Murray M.J. (2006). Chapter 9. Neuromuscular Blocking Agents. In G.E. Morgan, Jr., M.S. Mikhail, M.J. Murray (Eds), Clinical Anesthesiology, 4e.