Dantrolene

Dantrolene sodium, sold under the brand name Dantrium among others, is a postsynaptic muscle relaxant that lessens excitation-contraction coupling in muscle cells.[3][4][5] It achieves this by inhibiting Ca2+ ions release from sarcoplasmic reticulum stores by antagonizing ryanodine receptors.[6] It is the primary drug used for the treatment and prevention of malignant hyperthermia, a rare, life-threatening disorder triggered by ... [wikipedia]