The neuromuscular blocking effect of Org 9426. A new intermediately-acting steroidal non-depolarising muscle relaxant in man.

Org 9426, a new steroidal non-depolarising muscle relaxant, which is stable in solution, was studied in 30 anaesthetised (thiopentone, fentanyl, nitrous oxide) male patients, ASA 1 or 2. A dose-response curve for Org 9426 was constructed and the ED90, mean (SD), was found to be 0.36 (0.031) mg/kg. The onset of action was 3.8 (1.8) minutes, the clinical duration 17.4 (3.2) minutes, the total duration of action 31.9 (6.2) minutes and the recovery time 9.96 (3.2) minutes. No signs of histamine release or cardiovascular effects were observed. Org 9426 thus has a faster onset of action than vecuronium bromide or atracurium dibesylate.