What is "dantrolene"

n. A particular muscle relaxant.

Dantrolene sodium is a postsynaptic muscle relaxant that lessens excitation-contraction coupling in muscle cells. It achieves this by inhibiting Ca ions release from sarcoplasmic reticulum stores by antagonizing ryanodine receptors. It is the primary drug used for the treatment and prevention of malignant hyperthermia, a rare, life-threatening disorder triggered by general anesthesia. It is also used in the management of neuroleptic malignant syndrome, muscle spasticity (e.g. after strokes, in paraplegia, cerebral palsy, or patients with multiple sclerosis), and 2,4-dinitrophenol poisoning.

It is marketed by JHP Pharmaceuticals LLC as Dantrium (in North America) and by Norgine BV as Dantrium, Dantamacrin, or Dantrolen (in Europe). A hospital is recommended to keep a minimum stock of 36 dantrolene vials (720 mg) sufficient for a 70-kg person. As of 2015 the cost for a typical course of medication in the United States is 100 to 200 USD.