CLINICAL OBSERVATIONS ON THE NEUROMUSCULAR BLOCKING ACTION OF ORG 9426, A NEW STEROIDAL NON-DEPOLARIZING AGENT

SUMMARY The neuromuscular blocking effects of Org 9426, the 2-morpholino, 16-allyl-pyrrolidino derivative of the 3-desacetoxy analogue of vecuronium have been investigated in anaesthetized patients. Based on data from a pilot study, two doses, 250 and 500 μg kg −1 (estimated as the ED90 and 2 × ED 90 , respectively) were chosen. Org 9426 appeared to be six to eight times less potent than vecuronium and showed a faster rate of development of neuromuscular block, with good to excellent intubation conditions within 60 s after administration of a dose of 500 μg kg −1 . The duration of action and the recovery index appeared to be similar to those of vecuronium. Side effects were not noted. Org 9426 may have advantages over existing non-depolarizing neuromuscular blocking agents with respect to rate of development of good intubating conditions, and is stable in aqueous solutions.