Cholinesterase inhibitors can combat the impairment of cholinergic neurons in AD patients by slowing the degradation of acetylcholine released from synapses during neurotransmission. Memantine prevents the overstimulation of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors to prevent calcium-induced excitotoxicity, which may contribute to the pathogenesis of AD and other neurodegenerative conditions.