Malignant hyperthermia (MH) is one of the most devastating crises encountered in anesthesia.
MH is a rare life-threatening condition triggered by exposure to certain drugs used for general anesthesia (specifically all volatile anesthetics), nearly all gas anesthetics, and succinylcholine (a neuromuscular blocking/depolarizing muscle relaxant) in patients who have inherited a gene defect for malignant hyperthermia. It may be the cause of sudden, unexpected death in an individual undergoing surgery.
Since 1979, Dantrium® IV has been available for the treatment of an MH crisis and has contributed to a dramatic decline in deaths and/or resultant disabilities from the crisis. The mortality rate from malignant hyperthermia has dropped from 80% in the 1960s to currently less than 10%.1
Dantrium® IV is a sterile, non-pyrogenic, lyophilized formulation of dantrolene sodium for injection. Dantrium® IV is supplied in 70 mL vials containing 20 mg dantrolene sodium, 3000 mg mannitol, and sufficient sodium hydroxide to yield a pH of approximately 9.5 when reconstituted with 60 mL sterile water for injection USP (without a bacteriostatic agent).
The Malignant Hyperthermia Association of the United States (MHAUS) recommends a minimum stocking level of 36 vials of dantrolene sodium for injection (Dantrium® IV) for facilities that use triggering agents. This number is based on the amount of Dantrium® IV used to treat an MH episode for the average adult (70 kg) at the upper dosing limit of 10 mg/kg.2 However, the size of the patient and the severity of the reaction will dictate the number of vials needed. If you would like to order educational materials on how to prepare your facility for an MH crisis, please contact MHAUS at 800-98-MHAUS.
Management of MH crises requires various supportive measures individualized for the patient’s condition. Administration of Dantrium® IV is one component of therapy and should not be considered a substitute for these measures. Even when properly treated, an MH crisis can result in death. Adverse events with Dantrium® IV include loss of grip strength, weakness in the legs, drowsiness, dizziness, thrombophlebitis, and tissue necrosis/injection site reactions secondary to extravasation. There have been rare reports of pulmonary edema, urticaria and erythema. Please see accompanying full prescribing information for Dantrium® IV.
1 Krause T, Gerbershagen MU, et al. Dantrolene – A review of its pharmacology, therapeutic use and new
developments, Anaesthesia, 2004; 59(4): 364-373.
2 http://medical.mhaus.org/index.cfm/fuseaction/Content.Display/
PagePK/MedicalFAQs.cfm (accessed 6/30/09)
Available November 2, 2009
