Succinylcholine (Anectine) is an MH trigger. Generally injected intravenously, the drug is usually used to produce deep muscle relaxation in order to facilitate such procedures as intubation of the trachea. The onset of relaxation is very rapid and the duration is generally less than 10 minutes. Succinylcholine, introduced in the 1950s, is used primarily by anesthesia providers, emergency medicine physicians and others who are trained in management of the airway. Other adverse effects of the drug include massive increase in potassium levels leading to cardiac arrest in burn patients and patients with muscle disorders, muscle pain, and occasionally prolonged duration of action in some patients where the enzyme that degrades the drug is ineffective. However, by far the most dangerous complication of the use of Succinylcholine is MH.
There are other drugs that are not MH triggers (such as rocuronium or vecuronium) that produce rapid onset of paralysis like succinylcholine, but they are not used for this purpose very often because the duration of muscle weakness can be an hour or longer. However, a remarkable drug was developed about 10 years ago, called Sugammadex, that completely and rapidly reverses the weakness caused by rocuronium and vecuronium. As such, the potential exists for avoiding the use of succinylcholine and all the complications associated with its use. Sugammadex has been approved and has been used satisfactorily for many years in over 70 countries.
Despite several attempts to obtain FDA approval, only recently has an expert panel of the FDA recommended full approval of the drug.
Sugammadex, like many other drugs, is associated with an allergic reaction in a small number of patients, but the potential benefit of avoiding a drug that may trigger MH, as well as enhancing return of normal muscle strength in other situations, led the panel to recommend its approval. In discussing the acceptance of Sugammadex with MH experts in other countries, the only reservation I heard was the additional cost of the drug compared to succinylcholine. The company, Merck, has not indicated what the cost of the drug will be in the U.S. It will take some time for the medication to be approved and people trained to use the drug, but from the perspective of concern for avoiding an MH trigger, it is, in my opinion, a great advance.