New epidemiological study in malignant hyperthermia reinforces the effectiveness of Dantrium® in reducing fatal anaesthetic reaction
For the first time, a new Canadian epidemiologic study reveals that a 15.5 per cent incidence of adverse anaesthetic reactions is triggered by succinylcholine alone. In line with previous findings, the study also further underlines that early recognition and prompt administration of dantrolene intravenous are critical for patient survival and reduction of complications.
The study reviews one hundred twenty-nine proband* survivors of adverse anaesthetic reactions, whose malignant hyperthermia susceptible status was confirmed by caffeine-halothane contracture testing. Among the findings are lower than expected complication rates in anaesthetising facilities using either succinylcholine or volatile anaesthetic drugs.
Importantly, it also reports that dantrolene reduced the incidence of complications (e.g. renal and cardiac dysfunction, disseminated intravascular coagulation) in these patients. If given between 10 and 19 minutes after the start of malignant hyperthermia, the complication rate is under 20 per cent. An escalating relationship between time to administration was identified, showing that complications can reach 100 per cent when the administration of dantrolene was delayed beyond 50 minutes.
This study is worth noting because it also highlights how having dantrolene readily available can reduce the morbidity and mortality caused by malignant hyperthermia and therefore suggests the importance of reviewing stock levels in hospitals.
The incidence of malignant hyperthermia varies greatly among different populations due to genetic diversity. Recent data suggest the genetic predisposition may be as prevalent as 1 in 3,000 people.
Dr Gunilla Islander, Department of Anaesthesia, Lund hospital, Sweden commented; “These new data are very important as they emphasize that survival from a malignant hyperthermia crisis, a rare condition, is highly dependent on early recognition and prompt action, and that the rapid use of dantrolene can ensure patient survival”.
In Europe, DANTRIUM® (dantrolene) is commercialised by Norgine B.V. In December 2012, Norgine B.V. with the owners of SpePharm Holding B.V., created a joint venture company, SpePharm AG, which acquired the specialist hospital products of SpePharm Holding B.V. – DANTRIUM® IV, DANTRIUM® capsules, SAVENE®, XEROTIN® and PROTHER®.
About Malignant Hyperthermia
Malignant hyperthermia is an inherited, rare, life-threatening condition. Triggers for malignant hyperthermia include skeletal muscle relaxants such as succinylcholine and certain volatile anaesthetic gasses, one example of which is halothane.
Early recognition of a pending malignant hyperthermia crisis and immediate treatment are essential for the patient’s survival.
About dantrolene (DANTRIUM®)
Dantrolene IV is indicated for malignant hyperthermia and acts peripherally to lower the intracellular calcium concentration in the skeletal muscle.
This occurs by decreasing the release of calcium ions from the sarcoplasmic reticulum and inhibiting the influx of calcium into the myoplasm. Therefore, it effectively slows or stops the cycle of malignant hyperthermia.
Dantrolene oral capsule(s) is a muscle relaxant indicated for chronic spasticity. It is the only agent that acts directly at the level of the skeletal muscle and it therefore has a unique place among the muscle relaxants prescribed.
*Malignant hyperthermia often has a familial genetic lineage (autosomal dominant). In this study probands are individuals who presented with the first known cases of malignant hyperthermia in their families. These subjects then had a Caffeine-Halothane Contracture Test, a gold-standard test used widely in North America to confirm susceptibility to malignant hyperthermia.
 Sheila Riazi et al. Malignant Hyperthermia in Canada: Characteristics of Index Anesthetics in 129 Malignant Hyperthermia Susceptible Probands. Anesth Analg. 2013 Jul 10. [Epub ahead of print], doi: 10.1213/ANE.0b013e3182937d8b
 Glahn et al. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group. British Journal of Anaesthesia 105 (4): 417-20 (2010), doi: 10.1093/bja/aeq243