The invention relates to a liquid pharmaceutical composition for use in medical treatment, said liquid pharmaceutical composition being a monophasic aqueous solution of non-complexed 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone) and comprising at least 75 wt. % water and 0.2-9 mg/mL of edaravone, wherein the treatment comprises oral or gastric administration of 10-250 mL of the liquid pharmaceutical composition to provide 30-300 mg edaravone.