Changes in brain amyloid-β accumulation after donepezil administration.

Area of Science:

• Neurology
• Neuroscience
• Pharmacology

Background:

• Alzheimer's disease (AD) is characterized by amyloid-β (Aβ) plaque accumulation in the brain.
• Donepezil, an acetylcholinesterase inhibitor, has shown promise in reducing Aβ in mouse models of AD.

Purpose of the Study:

• To investigate the efficacy of donepezil in reducing brain Aβ accumulation in human patients with Alzheimer's disease.
• To determine if one year of donepezil treatment alters Aβ burden in AD patients.

Main Methods:

• Ten AD patients underwent two ¹¹C-Pittsburgh Compound B (PiB) PET scans approximately one year apart.
• Standardized uptake value ratio (SUVR) was calculated in Aβ-preferred regions, using the cerebellum as a reference.
• Patients received either 5mg or 10mg of donepezil daily.

Main Results:

• A significant increase in SUVR was observed between the first and second PET sessions (P=0.026).
• This indicates a higher brain Aβ accumulation after one year of donepezil treatment.
• The findings contradict previous results from mouse models.

Conclusions:

• One year of donepezil administration does not reduce, and may even increase, brain Aβ accumulation in human patients with Alzheimer's disease.
• Donepezil's efficacy in reducing Aβ burden may not translate from mouse models to human AD patients.
• Further research is needed to understand donepezil's long-term effects on Aβ pathology in humans.