epilepsy / parkinsons / migraines Flashcards
What are the common symptoms with parkinsons
tremor of rest
bradykinesia
tendency to stoop
mortality
What is the cause of parkinsons
degeneration of neurons in the substantial nigra
Which dopamine receptor is excitatory
D1
Which dopamine receptor is inhibitory
D2
What does a decrease in neurons cause
a decrease in cortical stimulation
What is the direct pathway in the brain dominated by
D1 receptors
What is a dopamine precursor
L-Dopa
What does levodopa do
crosses the BBB
actively taken up into neurons
converted into dopamine
Which enzyme converts L-dopa in dopamine
DA decarboxylase
What are the adverse affects of levodopa
Dyskinesia
hallucinations/confusion
Why can L-dopa cause hallucinations or confusion
when dopamine levels in the brain are disrupted in any way, it can cause forms of psychosis
If someone on L-dopa has symptoms of psychosis, how would you treat them
with antipsychotics (do so cautiously)
What is always given with L-dopa and why
carbidopa
allows L-dopa to fully cross the BBB without being converted to DA too early
Reduces peripheral side effects
What is the MOA of carbidopa
peripheral inhibitor of L-aa decarboxylase
Prevents conversion to DA in periphery
What is entacapone
Levodopa adjunct therapy
What is the MOA of entacapone
inhibits COMT
prevents degradation of levodopa
What is COMT
secondary pathway to metabolize levodopa, DA, and NE
What are the adverse effects of entacapone
dyskinesia
nausea
diarrhea
When is entacapone used for parkinsons treatment
When the disease progresses and the L-dopa/Carbidopa combo is no longer sufficient
When does L-dopa work the best in parkinsons treatment
The earlier in the disease you treat the better
What happens when someone is on L-dopa for a long time
motor fluctuation from receptor adaptation
-on/off effect
What is an example of an MAO B inhibitor
selegiline
What is the MOA for selegiline
Prevents metabolism of DA, NE, and serotonin
What is 5-HT
seretonin
What is the benefit of using Selegiline
Reduces the dose of levodopa needed
What drug is interchangeable with Selegiline
Rasagiline
What are the adverse effects of selegiline
Amphetamine - like side effects
Seretonin syndrome
sweating
arrhythmia
diarrhea
What is selegiline metabolized by and what is the product
Metabolized in the liver by CYP450
turns partially into amphetamine
What is a dopamine receptor agonist that is used in parkinsons treatment
Bromocriptine
Ropinorole
What is the MOA for Bromocriptine
Delay the need for L-Dopa or in advanced parkinsons
What is the adverse effect of bromocriptine
cardiac valve fibrosis
How is Ropinorole different from bromocriptine
Rompinirole is less selective
Rompinirole is also useful for restless leg syndrome
Ropinirole has less adverse effects
What are alternatives to Ropinirole
Pramipexole
How is Ropinirole metabolized
CYP450
What are adverse effects for ropinirole
Increased risky behavior
What is the MOA for Trihexyphenidyl
mACh receptor antagonist will allow for DA to work in the striatum
Helps reduce dyskinetic movement and spastic contraction
What are the adverse effects on Trihexyphenidyl
Anticholinergic effect (sedation/confusion/constipation/urinary retention)
Pharmakinetics: gets excreted unchanged
How is Trihexyphenidyl often administered
In combination with DA agonists
What is Benzotropine
A non-DA parkinsons treatment
Helps with excess amounts of dopamine
What can excessive dopamine cause
rigidity
What is amantadine
Antiviral
What is the MOA of Amantadine
Increases DA release and blocked the NMDA glutamate receptors
What are the adverse effects of amantadine
confusion
psychosis
Where is the neuronal loss in Huntingtons disease
Caudate/putamen
Striatum
Loss of GABA function
What is treatment for Huntingtons based on
The most pronounced symptoms
What is the mainstay therapy for Huntingtons
Neuroleptic D2 blockers
What is an example of a neuroleptic D2 blocker
Haloperidol
What is a drug that can be given for the treatment of chorea
deutetrabenazine
What is the MOA of deutetrabenazine
Inhibits neurotransmitter storage
which reduces uncontrolled hyperkinetic movements
How is duetetrabenazine metabolized
CYP450