Cholinesterase Inhibitor Discontinuation

There are no reliable findings from controlled trials about discontinuation of cholinesterase inhibitors from a patient and family perspective. It is unknown at what point these medications do not have effects, and how they can safely be discontinued. The investigators will identify Veterans who have been taking a cholinesterase inhibitor (CI) (donepezil or galantamine) for at least one year. After informed consent, the investigators will randomize them to Real Taper (half-dose of the CI they had taken for 3 weeks, then placebo for 3 weeks), or Sham Taper (continued full dose of the CI they had taken for 6 weeks). The pills will be blinded by over-encapsulating of the drug or placebo. An intake interview will ascertain history and measure behaviors, cognitive symptoms, and mood, as well as caregiver burden. Phone calls will assess treatment use and adverse events at week 2 and week 4. An exit interview at week 6 will measure the same variables as at baseline. Participants will be unblinded at that point so they will know which treatment had been used. A follow-up call at 12 weeks will ascertain ongoing treatment and any further adverse events. At any point in the study, participants and caregivers will be able to return to their pre-study dose of medication. The primary outcome is the percentage of participants who successfully complete a 6-week discontinuation. This will be compared between arms. Other outcomes related to medical events (e.g. hospitalizations, falls), symptoms (e.g. cognition, behaviors), and caregiver distress will be measured and compared.