Dantrolene
Dantrolene is the hydrazone resulting from the formal condensation of 5-(4-nitrophenyl)furfural with 1-aminohydantoin. A ryanodine receptor antagonist used for the relief of chronic severe spasticity and malignant hyperthermia. It has a role as a muscle relaxant, a ryanodine receptor antagonist and a neuroprotective agent. It is an imidazolidine-2,4-dione and a hydrazone. It is a conjugate acid of a dantrolene(1-).