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

The dose-response relationship and the time course of action of Org 7617, a short acting non-depolarizing neuromuscular blocking agent, were evaluated during thiopentone, fentanyl, halothane and N2O anaesthesia. Neuromuscular transmission was monitored mechanomyographically. The ED(50) and ED(90) were calculated after single bolus doses of the drug. Twelve, seven and three patients received 2.5, 3.75 or 5.0 mg . kg(-1) Org 7617, respectively. Neuromuscular block was characterized by a short lag time (average 30 s) and rapid development of neuromuscular block (69-84 s).Maximum block approximated to 66 %, 91 % and 95 %. and the duration until clinically adequate recovery (TOF ratio of 0.7) to 7.4, 12.1 and 12.2 min after 2.5, 3.75, 5 mg . kg(-1) of Org 7617, respectively. The calculated ED(50) and ED(90) were 1.8 and 3.4 mg . kg(-1).