American Board of Internal Medicine (ABIM) Certification Practice Exam

All cholinesterase inhibitors are approved for mild to moderate Alzheimer disease, except?

1. Rivastigmine

2. Galantamine

3. Donepezil

4. Memantine

The correct answer is: Donepezil

Donepezil is a cholinesterase inhibitor that is indeed approved for the treatment of mild to moderate Alzheimer's disease, making it the choice that doesn't fit the question. Cholinesterase inhibitors, including rivastigmine, galantamine, and donepezil, work by increasing levels of acetylcholine in the brain, which can help improve symptoms associated with Alzheimer's by enhancing neurotransmission. However, memantine is not a cholinesterase inhibitor but an N-methyl-D-aspartate (NMDA) receptor antagonist, specifically approved for moderate to severe Alzheimer's disease. The critical distinction here is that memantine does not function as a cholinesterase inhibitor; its mechanism of action differs significantly, targeting different aspects of neurological function. Therefore, while rivastigmine and galantamine are indeed approved for mild to moderate Alzheimer's disease alongside donepezil, memantine’s classification and indication place it outside the category of cholinesterase inhibitors.