BCHE and Alzheimer disease: Despite the intensive efforts in developing pharmaceutical agents for AD, only five have been approved by the US Food and Drug Administration (FDA) to date: cholinesterase inhibitors including Donepezil, Galantamine, and Rivastigmine, which could increase synaptic acetylcholine to improve learning and memory, and the NMDA receptor antagonist Memantine, as well as the most recently sanctified amyloid-beta (Aβ) oligomer monoclonal antibody, Aducanumab.