An object of the present invention is to provide a highly stable medicament comprising a pyrazolone derivative such as edaravone, which is free of sodium bisulfite. The present invention provides a medicament, comprising(a) a pyrazolone derivative such as 3-methyl-1-phenyl-2-pyrazolin-5-one；(b) a glutathione analogue, and(c) an aqueous solvent, which comprises none of sulfite, bisulfite, and pyrosulfite, and is subjected to deoxygenation treatment.
