 It has been reported that co-administration of ephedrine reduced the onset time of neuromuscular block of rocuronium 1-3. It also provided an improved condition for the rapid tracheal intubation 2,4. This beneficial effect was attributed to the increased cardiac output and tissue perfusion to muscle, and therefore, a more rapid delivery of rocuronium to the neuromuscular junction was achieved 4-5. If so, any drugs which decrease cardiac output consequently can prolong the onset time of rocuronium. 