Which reversible cholinesterase inhibitor for Alzheimer's disease is taken orally once daily?

Donepezil is a reversible cholinesterase inhibitor used in the management of Alzheimer's disease. It works by increasing levels of acetylcholine in the brain, which can help alleviate some cognitive symptoms associated with the disease. One key aspect of Donepezil is its dosing regimen; it is formulated to be taken orally once a day, which enhances patient compliance due to the convenience of not having to take multiple doses throughout the day.

In contrast, other options do not share this specific once-daily oral regimen. For instance, Galantamine is typically taken twice daily, and Rivastigmine has both an oral formulation and a patch, but its oral dosing is also not limited to once daily. Memantine, while used in Alzheimer's treatment, is not a cholinesterase inhibitor; instead, it acts on NMDA receptors and is not categorized with the cholinesterase inhibitors. This distinction further emphasizes why Donepezil is the correct choice in the context of the question, focusing specifically on oral administration and the requirement of a once-daily dosing schedule.