PROBLEM TO BE SOLVED: To provide a medicine that works against toxoplasma gondii in a host cell containing bradyzoite while it has low toxicity to the host cell, and does not induce tachyzoite to bradyzoite.SOLUTION: An anti-toxoplasma agent that is effective in preventing and/or treating toxoplasmosis such as visual impairment and cerebral toxoplasmosis has a piperazine compound such as hydroxyzine, cetirizine and cyclizine, an isomer thereof, a pharmaceutically acceptable salt thereof or a mixture thereof as an active ingredient.SELECTED DRAWING: NoneCOPYRIGHT: (C)2018,JPO&INPIT【課題】ブラディゾイトを含む宿主細胞内のトキソプラズマ原虫に対して作用する一方で宿主細胞への毒性が低く、かつタキゾイドをブラディゾイトに誘導しない薬剤の提供。【解決手段】ヒドロキシジン、セチリジン、及びシクリジン等のピペラジン化合物、その異性体、薬学的に許容されるそれらの塩又はこれらの混合物を有効成分とする、視力障害、トキソプラズマ脳炎等のトキソプラズマ症の予防及び/又は治療に有効な抗トキソプラズマ剤。【選択図】なし
