Donepezil is a prescription-only drug used to alleviate some of the symptoms of Alzheimer'splugin-autotooltip__plain plugin-autotooltip_bigAlzheimer's disease

"Alzheimer’s disease is a chronic progressive neuro-degenerative disorder characterised by three primary groups of symptoms. The first group (cognitive dysfunction) includes memory loss, language difficulties, and executive dysfunction (that is, loss of higher level planning and intellectual coordination skills). The second group comprises psychiatric symptoms and behavioural disturbances — for example, depression, hallucinations, delusions, agitation — collectively termed … disease. There are currently around 5 million prescriptions per year in the US alone. It's sold under the brand names of Aricept, Namzaric and others.

It's known that the drug is a centrally-acting inhibitor of enzymes called cholinesterases.

Donepezil binds reversibly to acetylcholinesterase, preventing acetylcholine hydrolysis, thereby increasing the availability of acetylcholine at the synapses and enhancing cholinergic transmission.

Source : StatPearls 2023

But the specific 'mechanism of action' with regard to Alzheimer's is currently unknown, and is currently thought to possibly also involve 'noncholinergic' mechanisms.

In addition to its cholinergic effects, some noncholinergic mechanisms have been proposed for donepezil. Notably, the drug upregulates nicotinic receptors in cortical neurons, which may contribute to its neuroprotective properties.

[ Source as above ]

Further reading, see: Wikipedia