CLINICAL-PHARMACOLOGY OF ORG-7617, A SHORT-ACTING NONDEPOLARIZING NEUROMUSCULAR BLOCKING-AGENT

The dose-response relationship and the time course of action of Org 76 17, 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 b lock (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, re spectively. The calculated ED(50) and ED(90) were 1.8 and 3.4 mg . kg( -1).