Doxacurium and mivacurium do not trigger malignant hyperthermia in susceptible swine.
The role of succinylcholine in the precipitation of malignant hyperthermia (MH) necessitates the testing of new neuromuscular relaxants for their ability to trigger MH in MH-susceptible swine before general human use. We tested doxacurium and mivacurium, two new nondepolarizing bis-benzylisoquinolinium neuromuscular relaxants, at ED95 and at four times ED95 doses in swine previously documented to be MH-susceptible. In none of the 16 animals was MH triggered after administration of these relaxants, whereas all animals developed fatal MH after administration of halothane or halothane plus succinylcholine. Muscle biopsy specimens taken before administration of the relaxant confirmed that all animals had increased sensitivity to halothane, caffeine, or both. Thus, we conclude that doxacurium and mivacurium are not triggering agents of malignant hyperthermia in MH-susceptible swine.
Sufit
R L
RL
Department of Neurology, School of Medicine, University of Wisconsin-Madison 53792.
Kreul
J F
JF
Bellay
Y M
YM
Helmer
P
P
Brunson
D B
DB
Will
J
J
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D005260:Female; D007546:Isoquinolines / Q000633:toxicity*; D008305:Malignant Hyperthermia / Q000209:etiology*; D000077590:Mivacurium; D009119:Muscle Contraction / Q000187:drug effects; D003473:Neuromuscular Nondepolarizing Agents / Q000633:toxicity*; D013552:Swine
D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D002110:Caffeine; D000077590:Mivacurium; C049429:doxacurium