Neurodegenerative and Movement Disorders Flashcards
what are the 2 main purposes of pharmacotherapy of Parkinsons
increase dopaminergic activity
decrease cholinergic activity
dopamine doesn’t cross the BBB, however its precursor __ does
L-dopa
how is dopamine able to cross the BBB
the prodrug L-dopa crosses the BBB and is converted to dopamine by dopa decarboxylase
what is the effect of dopamine binding to D2 and D3 receptors in the CNS
opens K+channels
most of L-dopa is metabolized in the intestines by MAO and decarboxylation, however some is metabolized in the periphery (blood) by __ and __
COMT
decarboxylation
L-dopa is administered with __ which functions as a __
Carbidopa
peripheral decarboxylase inhibitor
what is the function of Carbidopa
inhibition of peripheral decarboxylase and its metabolism of L-dopa in GIT and blood, therefore increasing CNS bioavailability in the CNS
common side effects of L-dopa include …
nausea/vomiting
orthostatic hypotension
cardiac arrhythmia
what is the main adverse effect of L-dopa
dyskinesias
dyskinesias caused by L-dopa can be decreased by adding what drug
amantadine
wearing off reactions of L-dopa are related to
gradually, the duration of L-dopa effect is decreased
*related to timing
on-off phenomenon with L-dopa
sometimes patients response to L-dopa, sometimes they don’t
*fluctuation in clinical response
what is one of the main drug interactions of L-dopa
vitamin B6
how does vitamin B6 interact with L-dopa
increases dopa decarboxylase
what is the drug of choice for Parkinsons
L-dopa
if L-dopa is ineffective, what drug is used as a backup
dopamine receptor agonist
dopamine receptor agonists are used for ___ and __
response fluctuation
refractory to levodopa
what is the main adverse effect of dopamine receptor agonists
pulmonary and retroperitoneal fibrosis
Cabergoline is a dopamine receptor agonist that leads to what adverse effect
cardiac valvulopathy
Pergolide is a dopamine receptor agonist that lead to what adverse effect
heart valve fibrosis
regurgitation
what type of drug can be given to delay the need for L-dopa
non-ergot derivative dopamine receptor agonist
what is the injectable dopamine agonist Apomorphine used for
advanced Parkinsons with intermittent off episodes
what is given prior to injection of dopamine agonist Apomorphine
anti-emetic (Trimethobenzamide or Domeperidone)
the injectable dopamine agonist Apomorphine is contradicted with use of what drugs
5-HT3 receptor blockers
*can lead to severe hypotension
