Discontinuation of Cholinesterase Inhibitors for the Treatment of Severe Alzheimer's Disease

Inclusion Criteria

• •Aged \>55 years
• •Meet Diagnostic and Statistical Manual - IV (DSM-IV) criteria for primary degenerative dementia
• •Meet National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for probable AD of at least one year's duration
• •Score ≤15 on the Mini-Mental State Examination (MMSE) (severe dementia)
• •Receiving donepezil (5 or 10 mg), galantamine (8, 16 or 24 mg) or rivastigmine (3, 4.5 or 6 mg oral) for at least 2 years, with a stable dose for at least 3 months prior to study entry
• •Patients with a current order for any regularly administered psychotropic (e.g. selective serotonin reuptake inhibitor (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), trazodone, atypical or typical antipsychotics) must have been on a stable dose for at least 1 month prior to study entry