Time Course of Action and Endotracheal Intubating Conditions of Org 9487, a New Short-Acting Steroidal Muscle Relaxant; A Comparison with Succinylcholine

Abstract

In a randomized study, we evaluated lag time (time from the end of injection of muscle relaxant until the first depression of the train-of-four response [TOF]), onset time (time from the end of injection of muscle relaxant until the maximum depression of the first twitch of the TOF [T1]), neuromuscular block, and endotracheal intubating conditions at 1 min after 1 mg/kg succinylcholine (n = 15) and 1.5 mg/kg Org 9487 (n = 30). Two minutes after administration of Org 9487, 15 of the 30 patients received neostigmine for reversal. Recovery of neuromuscular block after succinylcholine, Org 9487 without and Org 9487 with neostigmine were compared using the time until T1 was 90% for the succinylcholine group, and the time until TOF was 70% for the Org 9487 groups. Neuromuscular transmission was monitored mechanomyographically. Onset time was similar (67 [20] and 83 [38] s for succinylcholine and Org 9487, respectively) and endotracheal intubating conditions were also similar after both muscle relaxants. Times until clinically sufficient recovery of neuromuscular block induced by succinylcholine (time until T1 = 90%: 10.6 [3.3] min) and Org 9487 with neostigmine (time until TOF = 70%: 11.6 [1.4] min) were not different. In contrast, in the Org 9487 without neostigmine group, more time was required until complete recovery (24.1 [6.2] min) (P < 0.05). In conclusion, ORg 9487 is a muscle relaxant suitable for endotracheal intubation and short-lasting interventions.

Neuromuscular effects of rapacuronium in pediatric patients during nitrous oxide-halothane anesthesia: comparison with mivacurium

“…1 The purpose of this study is to describe the neuromuscular effects of rapacuronium in neonates and older pediatric patients during halothane-nitrous oxide anesthesia. This study was undertaken in two parts.…”

Clinical pharmacology of ORG 7617, a short-acting non-depolarizing neuromuscular blocking agent

“…In earlier clinical studies, under similar study conditions, with low potency steroidal compounds, i. e. rocuronium [8], Org 9273 [9] and Org 9487 [5], and in the current study of Org 7617, the time until the first measurable response (20-30 s) approximated the circulation time. Hence, diffusion to the site of action seemed to be rapid and similar to that of succinylcholine [10].…”

“…Org 7617 is the first non-depolarizing neuromuscular blocking agent shown in man to have a time course of action resembling that of the short acting depolarizing agent succinylcholine when studied under similar anaesthetic conditions and with an identical measurement protocol, i. e. mechanomyography with TOF stimulation [5].…”

Historia de los Bloqueadores Neuromusculares

“…Es el análogo 16N-alil-17b-propionato del vecuronio. Era el primer BNM no despolarizante que combinaba las atractivas características de rápido inicio de acción y corta a intermedia duración de acción 46 . Llamó la atención la rápida aprobación hecha por la FDA en 1999, cuando la droga recién comenzaba la fase clí-nica de investigación, cuando había pocos estudios en animales y muy pocos estudios en seres humanos publicados en la literatura médica.…”