Neurodegenerative diseases Flashcards
Drug classes in treatment for Alzheimees
- Cholinesterase Inhibitors
- NMDA receptor Antagonist
Cholinesterase inhibitors
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Razadylne)
NMDA receptor antagonist
Memantine (Namenda)
Mechanism of action for cholinesterase inhibitors
- Prevents action of acetylcholinesterase
- this increases acetlycholine in the synapse
Nausea
Bronchospasm
Cholinesterase inhibitors
Headache, Dizziness, Diarrhea
Cholineaterase inhibitors
and
NMDA receptor antagonists
- sedation
- fatigue
- hypertension
- rash
- weight gain
- urinary frequency
- anemia
NMDA receptor antagonists- Memantine
Memantine (Namenda) mechanism of action
- Block leaky channels to reduce calcium induced excitotoxicity
- Block leaky channels to reduce background noise and make signals relatively stronger
- Blocks the pathalogical activation of NMDA receptors
What is drug therapy for parkinsons aimed at
increasing dopamine or decreasing Acetylcholine to balance the two
Three mechanisms of action of dopiminergic agents
- increase amounts of dopamine in th Striatum
- incresed delivery or decreased degredation of dopamine
- Mimic the effects of dopamine - dopamine agonists
what is the mechanism of action of anticholonergic agents
Prevent cholonergic inhibition of dopamine release
First line of therapy for Parkinsons
Levadopa
80% of paitines show improvement, and 20% Regain normal function with levadopa therapy, but what else is very improtant about this therapy
Its effects wer off over time (2-3 years) likely due to advanced neuro degeneration
Levadopa mechanism of action
levadopa is converted to dopamine increasing dopamine in the striatum
Levadopa is converted to ____________providing dopamine in the striatum, this happens in the _________________. Levadopa is only needed in the _________ and large amounts of levadopa in the __________ causes problems. This is why Levadopa is dosed with ___________ a ________________ and ___________a ___________ which causes sthe same amount of Levadopa to reach the brain with a ____________ dose. ___________ is added when ________________ wanes.
- dopamine
- periphery and the brain.
- brain
- periphery
- Carbadopa a peripheral decarboxylase inhibitor
- Entacopne a COMT inhibitor
- smaller
- Entacapone
- Levadopa/Carbadopa
Acute side effects of Levadopa
Disappear after a few week s and include nausea, anorexia and hypotension
Sede effects of Levadopa
- involutary movements
- on-off effects (hypokinesia and improvements)
- Psychosis - schizophrinia like symptoms with excess domamine
Adverse drug interaction with Levadopa
MAO Inhibitors- will cause an overload of dopamine and NE
Levadopa when given alone is degraded by
Mosty decarboxylases and a little by COMT causing ittle to get to the brain
When levadopa is given with a DDC inhipibitor (Decarboylase inhibitor) ____________.
Dopamine is still broken down by COMT and not as much gets to the brain
Optimization of levadopa happens when
Levadopa is given with a DDC inhibitor and a COMT inhibitor - this allows for the most amount of the drug to get to the brain
Dopamine agonists
Pramipexole and Ropinirole
Highly selective for D2/D3 receptors
Pramipexole and Ropinirole
may cuase halucinations and compulsive behaviors
Pramipexole and Ropinirole
Increases dopamine in the synapes
Selegiline
MAO-B inhibitor
Selegiline
Because _________ is an MAO-B inhibitor it is not involed in _______________. It specifically decreases ____________. and does not have the _____________________
- Selegiline
- NE metabolism
- Dopamine degredation
- unwanted effects of non-selctive MAOIs
Enhances dopamine release into the synapse
Amantadine
Anticholinergic drug used for parkinsons
Benzotropine
MOA for anticholinergic drug for parkinsons
Benzotropine - causes a blockade of muscarinic receptors relieving the inhabition of dopaminergic neurons causing more dopamine release
Muscarinic receptors
in striatum where they inhibit dopamine release from dopamine neurons
Benzotropine side effects
Anticholinergic - Anti SLUDG
- dry mouth
- dry eyes
- urinary retention
- constipation
Clearance can be reduced by increasing urinary pH - ie giving bicarbonate
Memantine
Prolongtion of Succinylcholine
Cholinesterase inhibitors - Donepexil, Rivastigmine, Galamtamine
Assess for anticholinergic siede effects especially HR
Anticholinergic drugs like Benztropine - Decreased HR
avaoid drugs that impact cholinergic tone like TCA’s
Anticholinergic drugs - Benztropine
Evaluate for anticholinergic-like side effects
Amantadine
Rule out congestive heart failure side effect
Amantadine
- MUST receive q6-12 hours
- Administer 20 minutes pre-op and intraop to avoid SUDDEN sloss of effect and neuromuscular/respiratory failure
Levadopa decarboxylase inhibitors
effects include
- cardiac dysrhythmias
- adrenergic stimulation
- orthostatic hypotension
- GI
Levadopa decarboxylase inhibitors
Side effects include
- CV
- hypotension
- pleuropulmonary fibrosis
Synthetic dopamine agonists -Pramipexole and ropinirole
AVOID Ephedrine and Mepreidine
Selegiline (MAO-B inhibitor)
Use extreme caution with vasoactive medications
Selegiline (MAO-B inhibitor)
Pronounced effect with neuromuscular blockers, sedative agent, diuretics
Selegiline (MAO-B inhibitor)