PROBLEM TO BE SOLVED: To provide a method, targeting a histamine H3 receptor, for treating disorders such as cognitive deficit in schizophrenia, obesity, attention deficit hyperactivity disorder, pain, and Alzheimer's disease.SOLUTION: The present invention provides a cyclopropyl amide derivative represented by formula I, or enantiomer or diastereomer thereof, or pharmacologically acceptable salt thereof, or a mixture thereof.【課題】ヒスタミンＨ３受容体を標的とし、統合失調症の認知障害、肥満、注意欠陥多動性障害、疼痛、アルツハイマー病の障害を治療する方法の提供。【解決手段】式Ｉで表されるシクロプロピルアミド誘導体、若しくはそのエナンチオマー若しくはジアステレオマー、又はそれらの薬学的に許容しうる塩、或いはそれらの混合物。【選択図】なし
