Neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery with various antagonists in vitro
Okamoto, T.; Aoki, T.; Fukushima, K.; Yoneda, I.; Satoh, T.; Nagashima, H.
Masui. Japanese Journal of Anesthesiology 41(9): 1467-1473
1992
ISSN/ISBN: 0021-4892 PMID: 1433879 Document Number: 400730
We evaluated the neuromuscular blocking effect of ORG9426, a new non-depolarizing muscle relaxant, and its recovery by means of washout or by antagonists in vitro, using phrenic nerve-hemidiaphragm preparations of rats. IC50 and IC90 of ORG9426 in single twitch were 10.62 +/- 0.58 microM and 15.75 +/- 0.95 microM; and those in train of four ratio were 9.04 +/- 0.38 microM and 11.87 +/- 0.42 microM, respectively. The potency of ORG9426 in vitro was compared with those of other non-depolarizing muscle relaxants. The order of potency among the non-depolarizing muscle relaxants was the following: d-tubocurarine greater than pipecuronium greater than pancuronium greater than vecuronium greater than ORG9426. There was no difference between ORG9426 and vecuronium in the recovery from block with washout, neostigmine, 4-aminopyridine, 3, 4-diaminopyridine, and edrophonium. In conclusion, the potency of ORG9426 is relatively low, and it can be easily antagonized by anti-cholinesterases and aminopyridines.