Parkinson's Disease Pharmacotherapy Flashcards
(45 cards)
T/F: Treatments for Parkinson’s only manange the disease but do not delay or stop the disease
True
What are the six types of medications used to treat Parkinson’s Disease
1) Levodopa
2) Dopamine agonists
3) Monoamine oxidase (MAO) B inhibitors
4) Catechol-O-Methyl-Transferase (COMT) inhibitors
5) Amantadine
6) Anticholinergic agents
T/F: In Parkinson’s the Substantia Nigra is being destroyed leading to less Dopamine release causing the symptoms of the disease
True
How is Dopamine created and released at Nigrostriatal neurons
1) Tyrosine is converted to L-DOPA by tyrosine hydroxylase
2) L-DOPA is converted to dopamine by DOPA Decarboxylase (DDC)
3) Dopamine is stored in vesicles ready for release due to an action potential
4) Dopamine that is left over is brought back into the cell by the dopamine transporters
What is the enzyme that converts L-DOPA into an inert compound, converts Dopamine into an inert compound
COMT converts L-DOPA in 3-OMD, MAO-B and COMT convert dopamine into an inert compound
What drug is used to increase dopamine levels by being converted to dopamine
Levodopa
What are the dopamine agonists
Ropinirole, pramipexole, rotigotine, apomorphine
What are the MAO-B inhibitors
Selegiline, Rasagiline, Safinamide
What are the COMT inhibitors
Entacapone and Tolcapone
What drug has an unknown MOA but is theorized to cause exocytosis, agonist of dopamine and inhibit dopamine uptake
Amantadine
What is the benefit of using anticholinergics
Reduce how bad tremors are
Why cant just dopamine be given
It does cross the BBB
What is the biggest side effect of levodopa, why
Causes nausea and vomitting, when L-Dopa is converted to Dopamine in the periphery it binds to the chemoreceptor trigger zone (CTZ) outside the BBB thus causing nausea
T/F: Levodopa is given by itself so some patients can handle the nausea while others cannot
False: Carbidopa is given with Levodopa to cause less side effects
How does carbidopa aid in the efficacy of Levodopa
Carbidopa competitively inhibits Dopa Decarboxylase from converting Levodopa in the periphery allowing for less side effects and more Levodopa to enter the brain
What should be counseled about Carbi/Levo when given with food
Do not eat with a high protein meal because the bioavailability is reduced
What are the two most notable side effects of Carbi/Levo, others
Nausea and orthostatic hypotension/ confusion, delusions, agitation, psychosis, motor fluctuations, parkinsonism hyperpyrexia syndrome
What is a tip to not have nausea with Carbi/Levo
Slower transiotion with food, supplemental doses of carbidopa 30 minutes before, ondansetrons, certain anticholinergics
What should NOT be given with Carbi/Levo
Dopamine antagonist (Metoclopramide, Prochlorperazine, Promethazine)
What happens with longer Carbi/Levo use with regards to motor fluctuations
In the beginning the drug works quickly, however with disease progression and tolerance the drug wears off quicker and it takes higher concentrations to achieve an effect, there is also dyskinesia due to the drug as the disease progress ALL DUE TO INCREASED DEPENDENCE
T/F: Due to the wearing off effect of Carbi/Levo there is clenching of feet upon waking in the morning but this can be mittigated through wooden shoes and long acting Carbi/Levo
True
How is the off period managed
Take Carbi/Levo more frequently OR adding COMT inhibitors OR MAO-B inhibitor OR Dopamine Agonist
What are ways to manage dyskinesia due to Carbi/Levo use
Use lowest effective dose, addition of amantadine, change to or add MAO-B inhibitor, addition of COMT inhibitor, change to or add Dopamine agonist
What is Parkinsonism Hyperpyrexia Syndrome, symptoms
Patients are on Carbi/Levo for long periods of time and it is suddenly stopped/ mental status changes, rigidity, fever (possibly fatal)
