Intravenous Administration of Azumolene to Reverse Malignant Hyperthermia in Swine
Article first published online: 24 JUN 2010
Copyright © 2010 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 24, Issue 5, pages 1224–1228, September/October 2010
How to Cite
Do Carmo, P. L., Zapata-Sudo, G., Trachez, M. M., Antunes, F., Guimarães, S. E. F., Debom, R., Rizzi, M. D. R. and Sudo, R. T. (2010), Intravenous Administration of Azumolene to Reverse Malignant Hyperthermia in Swine. Journal of Veterinary Internal Medicine, 24: 1224–1228. doi: 10.1111/j.1939-1676.2010.0556.x
- Issue published online: 2 SEP 2010
- Article first published online: 24 JUN 2010
- Submitted September 23, 2009; Revised April 21, 2010; Accepted May 7, 2010.
- Skeletal Muscle
Background: The efficacy of intravenous (IV) administration of azumolene (Az), an analogue 30-fold more soluble than dantrolene, on pigs susceptible to malignant hyperthermia (MH) is incompletely understood.
Objective: To evaluate efficacy of Az on MH crisis in pigs.
Animals: Eight normal (MHN) and 7 susceptible to MH (MHS) pigs (Landrace × Large White × Pietran).
Methods: Prospective, laboratory trial. Hypermetabolic crisis was observed in MHS pigs, but not in MHN pigs, after a combined administration of inhaled halothane (1.5%) and IV injection of succinylcholine (SCh; 2.5 mg/kg). Susceptibility was confirmed using a caffeine and halothane contracture test. Az was administered 15 minutes after administration of SCh.
Results: Respiratory acidosis (pH 7.16 ± 0.02; Pco2, 46.2 ± 9.1 mmHg, HCO3, 22.5 ± 2.3 mmol/L), fever (38.2 ± 1.1°C), cardiac arrhythmias, and muscle contracture were observed in MHS pigs. MHS pigs (n = 5) treated with Az (2 mg/kg IV) survived the crisis with attenuation of signs (pH 7.30 ± 0.10; Pco2, 36.3 ± 4.5 mmHg; HCO3, 22.9 ± 2.3 mmol/L) and recovery of normal muscle tone and cardiac rhythm.
Conclusions and Clinical Importance: Az represents a possible substitute for dantrolene to reverse MH crisis in susceptible pigs.