There is provided a medicament for treating amyotrophic lateral sclerosis (ALS) or symptoms caused by ALS and/or suppressing the progression thereof, which is characterized in the usage, dosage and administration period of the pyrazolone derivative represented by the following formula (wherein each symbol indicates the same meaning as that defined in the specification):


< Modulators of cystic fibrosis transmembrane conductance regulator

> Novel formulations of pharmacological agents, methods for the preparation thereof and methods for the use thereof

~ 00446