BCHE and Alzheimer disease: So far, only five therapeutic strategies for cognitive impairment in AD cases have been approved in the United States, including the cholinesterase inhibitors (donepezil, galantamine, and rivastigmine), NMDA receptor antagonist (memantine) (Cummings et al., 2014), and the fixed-dose combination of donepezil and memantine for moderate and severe AD (Cummings et al., 2019).