Figure 13-18 Linear regression of the onset of neuromuscular blockade (ordinate) versus potency of a series of steroidal relaxants studied in the cat model by Bowman and colleagues.^[176] The data show that onset may be increased in compounds with low potency and encouraged the eventual development of rocuronium and rapacuronium. A, pipecuronium; C, pancuronium; D, vecuronium.