Which medication improves cognition and function in patients with Alzheimer's disease early in the disease process?

• A. Fluoxetine (Prozac)
• B. Haloperidol (Haldol)
• C. Levodopa (Sinemet)
• D. Donepezil (Aricept)

Answer: (D)

In Alzheimer's disease, loss of cholinergic neurons leads to reduced acetylcholine in brain regions important for memory and learning. Medications that boost acetylcholine levels can improve cognition and day-to-day functioning, especially in the early stages.

Donepezil is a reversible acetylcholinesterase inhibitor that crosses into the brain and prevents the breakdown of acetylcholine. By increasing acetylcholine in the CNS, it helps enhance cholinergic transmission in areas like the hippocampus and cortex, which can translate into better memory and functioning in the early disease course. It’s a symptomatic treatment that can modestly improve cognition and everyday abilities, though it does not slow the underlying disease.

The other options don’t fit this goal. Fluoxetine is an antidepressant that may help mood or behavior but does not directly improve cognitive function. Haloperidol is an antipsychotic used for agitation or psychosis and can worsen cognitive impairment in the elderly. Levodopa targets motor symptoms in Parkinsonian disorders and is not helpful for cognitive decline in Alzheimer's disease.