MS, Parkinson's and Alzheimers Drugs Flashcards
Alzheimer’s is a form of dementia that (does/ does not) have a distinct cause, like stroke or brain injury?
does not
Alzheimer’s causes problems in these 5 areas:
- Memory
- Language
- Judgment and Thinking
- Personality
- Perception
Alzheimer’s is divided into 2 general categories, they are?
Early onset and Late onset
If Alzheimer’s symptoms appear at age _______ , the diagnosis is considered early onset Alzheimers.
Before age 60
What contributes to early onset Alzheimers?
genetic factors
If symptoms of Alzheimers occur at age _________, the diagnosis is considered late onset Alzheimers.
after age 60
What is the prevalence of Alzheimers at 65 years of age?
5%
What is the prevalence of Alzheimers at age 95?
>90%
What 2 main things occur to the brain in Alzheimers pathology?
- Brain shrinkage
- Localized loss of neurons
What are the 3 hallmarks of Alzheimers?
- Decrease of cholinergic transmission
- Amyloid plaques (amyloid beta)
- Neurofibrillary tangles
A decrease in cholinergic transmission occurs at which two places in the brain?
The hippocampus and the frontal cortex
Because the hippocampus is affected in Alzheimers, you will see:
loss of memory and learning
Because the frontal cortex is affected in Alzheimers, you will see:
a loss in executive function
What is a neurofibrillary tangle?
aggregate of hyerphosphorylated tau protein
What is an amyloid plaque?
A plaque consisting of tangles of amyloid protein (insoluble fibrous protein aggregates)
What are the 2 main pharmacologic approaches to treating Alzheimer’s.
- Cholinesterase inhibitors
- NMDA receptor antagonists
Alzheimer’s disease inovolves a selective loss of ____________ neurons.
cholinergic
What is the purpose of cholinesterase inhibitors in brains affected by Alzheimers?
to restore cholinergic function
What do cholinesterase inhibitors do?
They prevent the breakdown of AcH by cholinesterases, leaving more AcH in in the neuromuscular junction
In the path of Acetylcholine, What happens in steps 1, 2, and 3.
- Choline 2. Acetyl CoA 3. Join to form acetylcholine
In the path of acetylcholine, What is happening in steps 4 and 5?
- AcH is packaged up to leave the axon, it then leaves the neuron and begins to cross the synapse 5. Acetylcholine crosses the synapse and reaches the nicotinic receptor on the receiving neuron causing a message to be sent.
In the path of acetylcholine, What is happening in step 6?
After the message has been sent, acetylcholinesterase is released into the synapse and breaks down acetylcholine, inactivating it.
Can cholinesterase inhibitors make up for the defect in cholinergic transmission?
No
Cholinesterase inhibitors are indicated for (mild/moderate/severe) Alzheimer’s?
mild to moderate
Do cholinesterase inhibitors improve congitive function?
There is a slight improvement in cognitive function
Do cholinesterase inhibitors halt Alzheimer’s disease?
Unfortunately No.
Give 3 examples of cholinesterase inhibitors.
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Razadyne)
By which route and how often are cholinesterase inhibitors given?
They are given PO and are given 1-2 x/ day
What are the 5 side effects of cholinesterase inhibitors?
nausea
diarrhea
dizziness
headache
bronchoconstriction
What is an NMDA receptor?
N-methyl-D-aspartate receptor is a glutamate receptor, which plays an important role in memory storage.
What does activation of the NMDA receptor do?
It opens an ion channel that is nonselective to cations.
When the NMDA receptor is activated, it opens the ion channel and ___ and ____ move into the cell, while ___ moves out.
Na+ and Ca++ move in and K+ moves out.
Activation of the NMDA receptor requires the binding of ______or ________ and the coagonist_________.
requires glutamate or aspartate and the coagonist glycine
The flux of ____ is the critical ionic flow that enhances synaptic plasticity and memory function.
Ca++
In cells damaged by Alzheimer’s there is an excess of ___________.
glutamate
What will an excess of glutamate do to neurons?
excessive gluatamate binds to NMDA receptors creating a chronic exposure of neurons to calcium which can speed up cell damage.
What do NMDA receptor antagonists do?
They block glutamate from attaching to NMDA receptor which prevents ionic flow through the channel including calcium, preventing damage to neurons by overexposing them to calcium.
Name an NMDA receptor antagonist?
Memantine (Namenda)
Memantine (Namenda) is used to treat _________ (mild/moderate/severe) cases of Alzheimer’s.
moderate to severe
Is there any clinical benefit to using Namenda (Memantine)?
There are only very modest benefits.
Name 10 side effects of Namenda (Memantine).
- Dizziness
- Headache
- Fatigue
- Sedation
- Hypertension
- Rash
- Diarrhea
- Weight gain
- Urinary frequency
- Anemia
Name the receptor in this picture.
NMDA receptor
What is excitotoxicity?
Pathological process in which nerve cells are damaged and killed by excessive stimulation by neurotransmitters.
What is synaptic plasticity?
a general term used to describe long-term changes in synaptic connectivity and efficacy, following physiological alterations in neuronal activity (as in learning and memory)
What does memantine do to plastic processes?
It improves them
What are the 2 ways memantine works?
- Blocks leaky channels to help prevent calcium related excitotoxicity
- Blocking leaky channels helps reduce background noise which makes signals relatively stronger
Do NMDA antagonists or cholinesterase inhibitors stop Alzheimer’s?
No, they do not cure or stop the progression of the disease.
What is APP?
Amyloid precursor protein
Amyloid beta protein makes the ____________.
amyloid beta plaque
In the non-amyloidogenic pathway, APP protein gets cleaved by ___________ and no amyloid Beta protein is formed.
alpha secretase, once cleaved gamma secretase forms the correct protein.