Alzheimer’s Disease Drugs

Snapshot

• A 65-year-old man is brought by his daughter to the neurologist for the management of his recently diagnosed Alzheimer’s dementia. The daughter reports foregetfulness at times and has noticed few instances where he was confused in familiar places. She denies any major changes in his personality or hallucinations. The patient was started on donepezil for the patient’s mild Alzheimer’s  dementia.

Introduction

• A neurodegenerative disorder that is the most common cause of dementia
  • etiology is unknown; however certain genetic mutations have been described
  • decreased acetylcholine (ACh) appears to be associated with Alzheimer’s disease
    • ACh appears to be involved in memory
    • choline acetyltransferase activity—involved in ACh synthesis—seems to be decreased in the cerebral cortex, hippocampus, and amygdala in patients with Alzheimer’s disease
• Acetylcholinesterase inhibitors 
  • donepezil, rivastigmine, and galantamine 
    • increases ACh concentration
    • can be used for mild-to-moderate Alzheimer’s
    • improve symptoms but not prognosis 
  • toxicity
    • nausea, dizziness, and insomnia
• N-methyl-D-aspartate (NMDA) receptor antagonist
  • memantine 
    • can be used for moderate-to-severe Alzheimer’s
    • believed to decrease intracellular calcium accumulation to aid in the prevention of excitotoxic neuronal damage 
    • toxicity
      • commonly is dizziness, headache, and confusion