- Naive to approved or unapproved cholinesterase inhibitors (Aricept, Exelon, Cognex, Reminyl/Razadyne, metrifonate, physostigmine) is preferred. However, prior use of these medications is allowed, provided that the medication was discontinued at least 3 months prior to screening and that it was not discontinued for lack of tolerability or efficacy or for the sole purpose of enrolling the patient in the study. The exception to this prior use is that subjects who participated in the Phase II study E2020-A001-219 (A2501059) are not eligible.