<p>Memantine and donepezil hydrochlorides extended-release capsules contain two approved medications: memantine hydrochloride extended-release and donepezil hydrochloride. Each of those medications is postulated to have a different mechanism in Alzheimer&rsquo;s disease.<br />
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<strong>Memantine</strong>: Persistent activation of central nervous system NMDA receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of Alzheimer&rsquo;s disease. Memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive (open channel) NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels. There is no evidence that memantine prevents or slows neurodegeneration in patients with Alzheimer&rsquo;s disease.<br />
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<strong>Donepezil</strong>: Current theories on the pathogenesis of the cognitive signs and symptoms of Alzheimer&rsquo;s disease attribute some of them to a deficiency of cholinergic neurotransmission. Donepezil is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine in the central nervous system through reversible inhibition of its hydrolysis by acetylcholinesterase. There is no evidence that donepezil prevents or slows neurodegeneration in patients with Alzheimer&rsquo;s disease.</p>