Dose-response relation, neuromuscular blocking action, intubation conditions, and cardiovascular effects of Org 9273, a new neuromuscular blocking agent.
The ED50 and the ED90, the time-course of the neuromuscular block, the intubation conditions, and the cardiovascular effects of Org 9273, a new steroidal nondepolarizing neuromuscular blocking agent, have been evaluated in 41 anesthetized patients. From cumulative dose-response curves the ED50 and ED90 were calculated to be 175 and 300 micrograms/kg, respectively. The time-course of neuromuscular blockade after 300- and 500-micrograms/kg doses of Org 9273 appeared to be similar to that of equipotent doses of vecuronium. The neuromuscular block was characterized by a fast initial rate of block development. High-dose Org 9273 (1 mg/kg = 3-4 times the ED90) had a clinical duration comparable to an intubating dose of pancuronium, but a considerably more rapid onset and recovery index. Three hundred micrograms per kilogram and 500 micrograms/kg Org 9273 produced good to excellent intubation conditions 1 min after administration. Org 9273 in a dose of 0.5-2 times the ED90 produced no cardiovascular changes; however, 3-4 times the ED90 increased heart rate 20%-25% (P less than 0.001), probably due to a vagolytic effect.
van den Broek
L
L
Institute for Experimental Anesthesiology, University of Groningen, The Netherlands.
Lambalk
L M
LM
Richardson
F J
FJ
Wierda
J M
JM
D000284:Administration, Oral; D000328:Adult; D000762:Anesthesia Recovery Period; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008875:Middle Aged; D009466:Neuromuscular Blocking Agents / Q000494:pharmacology*; D009469:Neuromuscular Junction / Q000187:drug effects*; D010197:Pancuronium / Q000494:pharmacology; D014673:Vecuronium Bromide / Q000031:analogs & derivatives* / Q000494:pharmacology
D009466:Neuromuscular Blocking Agents; C068928:Org 9273; D014673:Vecuronium Bromide; D010197:Pancuronium