Vecuronium (ORG-NC-45)

Abstract

Vecuronium bromide (ORG-NC-45, Norcuron), henceforth called simply vecuronium, is the monoquaternary homologue of pancuronium. Vecuronium differs from pancuronium in that the methyl group on the 203b2-nitrogen atom of the latter is lacking (Fig. 1). Vecuronium is one of a series of amino steroidal derivatives, the synthesis and chemical properties of which have been described by Buckett et al. (1973), and more recently by Savage (1980, 1981) and Savage et al. (1980). Vecuronium was selected for further study from a series of closely related analogues on the grounds that, in the cat, it exhibited pronounced neuromuscular blocking activity coupled with only very weak actions at sympathetic ganglia and on the cardiac vagus (Durant et al. 1979 c). Since the first description of its properties, vecuronium has undergone extensive additional study both in animals (as described in this chapter) and in humans (as described by Miller in Chap. 28). Much of the work up to the end of 1979 is described in the proceedings of a symposium edited by Bowman and Norman (1980), and short reviews have also been published by Booij et al. (1981 a) and Durant (1982). With the knowledge of structure-activity relations available at the time, Durant et al. (1979 c) concluded that the conformation of the D ring acetylcholine-like fragment of pancuronium, which is known to have a different molecular geometry and electronic structure from that of the A ring (Savage et al. 1971), while intrinsically suited to the neuromuscular cholinoceptor, is relatively incompatible with the cardiac muscarinic receptor.