Alzheimer's and Dementia Flashcards
What is dementia?
Loss of memory and other intellectual functioning which interferes with daily life?
Give three types of dementia other than Alzheimer’s
- Vascular dementia - post-stroke with rapid course
- Mixed dementia - vascular + Alzheimer’s
- Lewy body dementia - Progressive and rapid dementia with fluctuating cognition. Movement disturbances and psychoses with interruption of REM sleep is common. (Robin Williams)
What is MCI and how is it relevant to AD?
Mild cognitive impairment - cognitive decline greater than expected for one’s age / education.
May be the pre-dementia / transitional state to AD
What are the later cognitive abilities affected by AD and what is this called?
Ability to calculate and use common tools (ideomotor apraxia)
What is the most common cause of death due to AD?
Complications of immobility (like PD) -> pneumonia and pulmonary embolism
What appears in the brain in Alzheimer’s disease? What are they made of?
Atrophy of cerebral cortex, with beta-amyloid plaques outside the nerves, and neurofibrillary tangles made out of hyperphosphorylated tau protein (stabilizes microtubules normally)
Give the three acetylcholinesterase inhibitors used for the treatment of Alzheimer’s dementia. Give whether these drugs are reversible or irreversible.
- Donepezil
- Rivastigmine
- Galantamine
All are reversible, but rivastigmine is noncompetitive
What drug is preferable of these three and why specifically?
Rivastigmine - has no drug-drug interactions in metabolism, metabolized by cholinesterase hydrolysis
Donepezil and Galantamine are metabolized by CYP2D6 and CYP3A4
What is the first disease-modifying drug of Alzheimer’s and how does it work?
Memantine - uncompetitive NMDA receptor antagonist, stabilizes inactive state of the NMDA channel and prevents calcium passage.
NMDA is thought to cause excitotoxicity
What other symptoms of Alzheimer’s does memantine treat and what can it be used with? Why?
Manages aggression / agitation as well
Can be used with cholinesterase inhibitors because memantine is excreted in the urine unchanged -> no drug interactions
What are the psychotic symptoms of Alzheimer’s? What drugs can treat these?
Outbursts, restlessness, hallucinations
Treat irritability with antidepressants, and restlessness with anxiolytics
Why should antipsychotic drugs not be used in the treatment of Alzheimer’s disease?
Black box warning of 2x increased risk of death due to heart attack and infections
How is psychosis in Lewy body dementia treated? Why?
Clozapine or pimavanserin,
APDs have a very high risk as well -> sedation, parkinsonism, neuroleptic malignant syndrome
Give three drug targets of new anti-Alzheimer’s therapies.
- Anti-amyloid therapies - active or passive immunization
- Gamma-secretase inhibitors -> inhibit the enzyme which cleaves amyloid precursor proteins to alpha-beta.
- Amyloid aggregation inhibitors
What is the problem with gamma-secretase inhibitors?
The gamma-secretase enzyme has many other functions in the brain than just cleavage of amyloid precursor protein.