ACHE and Alzheimer disease: Of the AChE inhibitors, only donepezil has been confirmed to be effective for indices including activities of daily living, and there is insufficient evidence for the other 2 drugs.[4,5] In the case of donepezil, a survey of therapeutic drugs prescribed to a large number of patients showed that the continuation rates after 6 and 12 months were extremely low, at 64.5% and 40.0%, respectively, because of uncertain effects.[6] The development of new symptom-ameliorating drugs for mild AD is important.