Dose-response and time-course of action of rocuronium bromide

Rocuronium is a new aminosteroidal muscle relaxant, the main feature of which is a low potency compared to other aminosteroidal muscle relaxants. The ED95 is approximately 0.3 mg kg-1, although the estimated potency may vary slightly with different modes of stimulation and under different anaesthetic techniques. The low potency is associated with a rapid onset of effect, a 2-3 x ED95 dose producing the maximum effect in 1-2 min. The duration of action is, however, comparable to other intermediate drugs such as atracurium and vecuronium. The estimated potency is similar in adults and the elderly, although the ED95 may be slightly higher in children. Rocuronium is affected in the same way as vecuronium by the use of volatile anaesthetic agents.